Process to form light-receiving member with outer layer made by alternately forming and etching

ABSTRACT

In a reactor capable of reducing an internal pressure thereof, a non-single-crystalline material layer containing at least one kind of carbon atoms, hydrogen atoms or nitrogen atoms is formed and etched on a non-single-crystalline photoconductive layer mainly composed of silicon atoms, formed on a substrate, under application of a high-frequency power of 50 MHz to 450 MHz, and the formation and the etching are alternately repeated plural times to form a surface layer. 
     A light-receiving member having such a surface layer does not damage cleaning performance over a long period of time, hardly allows adhesion of corona discharge products, and can be free from faint images, smeared images and uneven image density even if no heating means for the drum is provided.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to a process for producing a light-receivingmember, a light-receiving member produced by the method, anelectrophotographic apparatus having the light-receiving member, and anelectrophotographic method using the light-receiving member. Moreparticularly, it relates to a process for producing a light-receivingmember that has a superior cleaning performance and can obtainhigh-quality images free of faint images and smeared images in anyenvironment, an electrophotographic apparatus having the light-receivingmember, and an electrographic method using the light-receiving member.

2. Related Background Art

As materials for light-receiving members to be used inelectrophotographic photosensitive members, inorganic materials such asselenium, cadmium sulfide, zinc oxide and amorphous silicon (hereinafterreferred to as "a-Si") and organic materials are proposed in variety. Ofthese, non-single-crystalline deposited films containing silicon atomsas a main component, typified by a-Si, have been proposed as materialsfor photosensitive members having a high performance and a highdurability and free from environmental pollution, as exemplified byamorphous deposited films of a-Si containing hydrogen and/or a halogensuch as fluorine or chlorine (e.g., hydrogen or halogen compensatesdangling bonds). Some of these have been put into practical use.

U.S. Pat. No. 4,265,991 discloses a technique concerning anelectrophotographic photosensitive member comprising a photoconductivelayer mainly formed of a-Si.

Such a-Si type photosensitive members typified by a-Si have advantagesthat they have a high surface hardness, exhibit a high sensitivity tolong-wavelength light of semiconductor lasers (770 nm to 800 nm) or thelike and also are almost free from deterioration due to repeated use.Hence, they are put into wide use in photosensitive members forelectrophotographic apparatus as exemplified by high-speed copyingmachines and LBPs (laser beam printers).

As processes for forming such silicon type non-single-crystallinedeposited films, a number of processes are known in the art, asexemplified by sputtering, a process in which a material gas isdecomposed by heat (thermal CVD), a process in which a material gas isdecomposed by light (optical CVD), and a process in which a material gasis decomposed by plasma (plasma-assisted CVD). In particular,plasma-assisted CVD, i.e., a process in which a material gas isdecomposed by glow discharge or the like generated by utilizing a directcurrent, a high-frequency (RF or VHF) or a microwave to form a depositedfilm on any desired substrate such as glass, quartz, heat-resistantsynthetic resin film, stainless steel or aluminum is being widely putinto practical use not only in the process for forming amorphous-silicondeposited films for use in electrophotography but also in processes forforming deposited films for other uses. Apparatuses therefor are alsoproposed in a wide variety.

In recent years, taking into account its application inelectrophotographic photosensitive members, it is strongly sought toimprove film quality and processability, and various measures arestudied to do so.

In particular, a plasma-assisted process making use of high-frequencypower is widely used because of its various advantages such that it hasa high discharge stability and can be used to form insulating materialssuch as oxide films and nitride films.

Incidentally, in recent years, plasma-assisted CVD carried out at a highfrequency of 20 MHz or above using a parallel flat plate typeplasma-assisted CVD apparatus, as reported in Plasma Chemistry andPlasma Processing, Vol. 7, No. 3 (1987), pp. 267-273, has attractednotice, which shows a possibility of improving the deposition ratewithout a lowering of the performance of deposited films by making thedischarge frequency higher than 13.56 MHz conventionally used. Makingthe discharge frequency higher in this way is also reported in respectof sputtering, and has been widely studied in recent years.

Now, as charging and charge-eliminating means of conventionallight-receiving members of various types including a-Si light-receivingmembers, a corona assembly (corotron, scorotron) is used which comprisea wire electrode (e.g., a metal wire such as a tungsten wire of 50 to100 μm diameter, coated with gold) and a shielding plate in almost allcases. More specifically, corona electric currents generated by applyinga high voltage (about 4 to 8 kV) to the wire electrode of the coronaassembly are made to act on the surface of the light-receiving member tocharge the surface of the light-receiving member and eliminate chargestherefrom. The corona assembly is superior in uniform charging andcharge elimination.

However, corona discharge is accompanied by generation of ozone (O₃) ina fairly large quantity. The generated ozone oxidizes nitrogen in theair to produce nitrogen oxides (NO_(x)). The nitrogen oxides thusproduced further react with water in the air to produce nitric acid andthe like. The products produced by corona discharge (hereinafterreferred to as "corona discharge products") such as nitrogen oxides andnitric acid may adhere to and deposit on the light-receiving member andits surrounding machinery to contaminate their surfaces. Such coronadischarge products have so strong a moisture absorption that thelight-receiving member surface having adsorbed them exhibits a lowresistance because of the moisture absorption of the corona dischargeproducts having adhered thereto, so that the ability of charge retentionmay substantially lower on the whole or in part to cause faulty imagessuch as faint images and smeared images (a state in which the charges onthe surface of the light-receiving member leak in the surface directionto cause deformation, or no formation, of patterns of electrostaticlatent images).

Corona discharge products having adhered to the inner surface of theshielding plate of the corona assembly evaporate and become liberatednot only while the electrophotographic apparatus is operating but alsowhile the apparatus is not operating, e.g., at night. The coronadischarge products having thus evaporated and become liberated adhere tothe surface of the light-receiving member at its part corresponding tothe discharge opening of the corona assembly to cause further moistureabsorption. Hence, the surface of the light-receiving member may have alow resistance. Thus, the first copy initially outputted when theapparatus is again operated after inactivation, or copies on severalsheets subsequent thereto, tend(s) to have faint images or smearedimages occurring at the area corresponding to the opening of the coronaassembly. This tends to occur especially when the corona assembly is anAC corona assembly. Moreover, in the case when the light-receivingmember is an a-Si type light-receiving member, the faint images orsmeared images due to the corona discharge products may become a largeproblem.

More specifically, a-Si type light-receiving members have a little lowercharging and charge elimination efficiency than other light-receivingmembers (since the former requires a larger amount of corona chargingelectric currents in order to obtain the desired charging and chargeelimination potential), and hence the charging and charge elimination bycorona discharge applied onto the a-Si type light-receiving members arecarried out while greatly increasing the amount of charging electriccurrents. This is accomplished by increasing the voltage applied to thecorona assembly compared to other light-receiving members.

The a-Si type light-receiving members are mostly used in high-speedelectrophotographic apparatus. In such a case, the amount of chargingelectric currents may reach, e.g., 2,000 μA.

Since the amount of corona charging electric currents is proportional tothe quantity of ozone produced, the ozone may be produced in anespecially large quantity when the light-receiving member is an a-Sitype light-receiving member and the charging and charge elimination arecarried out by corona charging. Hence, the faint images or smearedimages due to the corona discharge products may become a large problem.

In addition, in the case of the a-Si type light-receiving members, theyhave a much higher surface hardness than other photosensitive members.Accordingly, any deposits on the light-receiving member can be etchedand removed only with difficulty during the step of cleaning or thelike, so that the corona discharge products adhered to the surface ofthe light-receiving member tend to remain.

Accordingly, in conventional cases, a heater for heating thelight-receiving member is provided inside the light-receiving member orhot air is blown to the light-receiving member by means of a hot-airblower and the surface of the light-receiving member is heated (to 30°C. to 50° C.) to keep the surface of the light-receiving member dry sothat the corona discharge products having adhered to the surface of thelight-receiving member can be prevented from absorbing moisture andmaking the surface of the light-receiving member exhibit a lowresistance, to thereby prevent the phenomenon of faint images or smearedimages. Such measures have been taken in some cases. Especially in thecase of the a-Si type light-receiving members, this heating and dryingmeans is incorporated in the electrophotographic apparatus as anessential means in some cases.

The developing assembly of such an electrophotographic apparatus has arotary cylindrical developer carrying member internally provided with,e.g., a movable magnet. On this carrying member, a thin layer of adeveloper, i.e., a toner or a mixture of a toner and a carrier, isformed, and then the developer is electrostatically transferred to alight-receiving member on which an electrostatic latent image has beenformed. This system is widely employed. Japanese Patent ApplicationLaid-open No. 54-43037, No. 58-144865, No. 60-7451 and so forth discloseone example of such a system. As developers, a developer containingmagnetic particles, i.e., the mixture of a toner and a carrier or adeveloper containing magnetite or the like in the toner and containingno carrier can be used.

In this system, by the heat from the light-receiving member, the part ofthe rotary cylindrical developer carrying member facing thelight-receiving member expands, so that the distance between the rotarycylindrical developer carrying member and the light-receiving memberbecomes short at the portion for applying the developer. This makes theelectric field therebetween stronger to make it easier for the developerto be transferred. This also allows the portion of the developercarrying member opposite to that portion to have a longer distancebetween them, so that the electric field becomes smaller to make it moredifficult for the developer to be transferred than usual in some cases.As the result, the image density may become high or low due, in part, tothe rotational period of the rotary cylindrical developer carryingmember. Occurrence of such a phenomenon may cause substantial damage tothe quality of an output image of the electrophotographic apparatus.Accordingly, it has been sought to provide a light-receiving member thatrather causes faint images nor smeared images even if thelight-receiving member is not heated.

In addition, in an electrophotographic apparatus that successivelyrepeats the steps of charging, exposure, development, transfer,separation and cleaning for performing scrape cleaning by means of ablade, such repeated operation may cause a gradual increase in thefrictional resistance of the surface of the light-receiving member. Anincrease in the frictional resistance results in a great reduction ofcleaning performance in the removal of a residual developer (or toner).If the copying steps are repeated in such a state, fine particles of thedeveloper or those of external additives such as strontium titanate andsilica contained in the developer may scatter to adhere to the wireelectrode of the corona assembly (hereinafter referred to as "coronaassembly wire") to cause discharge non-uniformity. Once the dischargenon-uniformity has been caused by the wire contamination of the chargingassembly, blank areas in lines, scale-like (or wavy) fog spreading overthe whole image, black spots (0.1 to 0.3 mm diameter) locally occurringwithout periodicity, and the like may occur to cause a great reductionof the quality of output images. Also, once the corona wirecontamination has occurred, an abnormal discharge is caused between thecontaminated portion and the light-receiving member, so that the surfaceof the light-receiving member may break to cause faulty images.

SUMMARY OF THE INVENTION

The present invention was made in order to solve the problems discussedabove. Accordingly, objects of the present invention are: to provide alight-receiving member that has a low frictional resistance; to preventtoner from scattering and causing contamination of the corona assemblywire in electrophotographic apparatus that successively repeat the stepsof charging, exposure, development, transfer, separation and cleaningfor performing scrape cleaning by means of a blade; to provide alight-receiving member substantially free of adhesion of the coronadischarge products caused by corona charging, to provide alight-receiving member that can produce high-quality images free offaint images and smeared images without regard to environmentalconditions and without providing any means for heating thelight-receiving member, and to provide an electrophotographic apparatuscomprising such a light-receiving member and a process for producingsuch a light-receiving member.

Another object of the present invention is to provide a process forproducing a light-receiving member, which comprises repeating pluraltimes the steps of alternately forming a layer of anon-single-crystalline material containing at least one kind of carbonatoms, oxygen atoms and nitrogen atoms and thereafter, etching the layeron a substrate in a reactor capable of reducing an internal pressurethereof to form a surface layer; a light-receiving member produced bysuch a process; an electrophotographic apparatus comprising thelight-receiving member and an electrophotographic method using thelight-receiving member.

Still another object of the present invention is to provide a processfor forming a light-receiving member which comprises the steps ofetching on a substrate, forming a layer of a non-single-crystallinematerial containing at least one kind of carbon atoms, oxygen atoms andnitrogen atoms, and etching the layer; a light-receiving member producedby the process; an electrophotographic apparatus comprising thelight-receiving member; and an electrophotographic method using thelight-receiving member.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagrammatic cross section to show a preferred example ofthe configuration of a surface layer of the light-receiving memberaccording to the present invention.

FIG. 2 is a diagrammatic view to show an example of the construction ofa deposition apparatus used to produce the light-receiving member byVHF-PCVD (very high frequency)-(plasma-assisted chemical vapordeposition) applicable in the present invention.

FIGS. 3A and 3B are diagrammatic cross sections to show examples of theconstitution of the light-receiving member according to the presentinvention.

FIG. 4 is a diagrammatic cross section to illustrate an example of anelectrophotographic apparatus.

FIG. 5 is a diagrammatic cross section to show another example of adeposition apparatus used to produce the light-receiving member byVHF-PCVD applicable in the present invention.

FIG. 6 is a diagrammatic transverse cross-section of the depositionapparatus shown in FIG. 5.

FIG. 7 is a diagrammatic view to illustrate the whole construction ofthe deposition apparatus shown in FIG. 5.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention provides a process for producing a light-receivingmember comprising a surface layer composed of a non-single-crystallinematerial containing at least one kind of carbon atoms, oxygen atoms andnitrogen atoms, which comprises repeating alternately film formation andetching plural times in a reactor; a light-receiving member produced bysuch a process; an electrophotographic apparatus comprising thelight-receiving member; and an electrophotographic method using thelight-receiving member.

In the present invention, film formation and/or etching is preferablycarried out by using a high-frequency power having a discharge frequencyof from 50 MHz to 450 MHz. The surface layer may further contain siliconatoms and/or hydrogen atoms.

In the present invention, fluorine atoms may preferably be contained inthe whole region in the thickness direction of the surface layer.

In the etching, it is desirable to use a fluorine type gas as an etchinggas, and to etch the layer preferably in a depth of 20 Å or more, andmore preferably 50 Å or more.

The fluorine type gas may preferably be CF₄, CHF₃ or ClF₃.

For the surface layer formed by film formation and etching which arecarried out once, it is desirable to have a layer thickness ofpreferably from 10 Å to 2,000 Å, and more preferably from 40 Å to 1,000Å.

The surface layer may be provided on a light-receiving layer formed on asubstrate. The light-receiving layer may have photoconductivity, and thelight-receiving layer may comprise a photoconductive layer. Thephotoconductive layer may be of a single-layer type or may be of afunction-separated type. Further, carbon atoms may be preferablycontained in the surface layer.

In the present invention, fluorine atoms can be incorporated in thesurface layer by the method as mentioned above so that the surface layercan be improved in water repellency to thereby effectively prevent thecorona discharge products from adhering.

The present inventors made studies on the surface layer containingsilicon atoms, carbon atoms and hydrogen atoms, in order to achieve itshigher water repellency. As a result, they have discovered that asurface layer having a very high water repellency and durability can beobtained when dangling bonds of carbon atoms or C-H bonds present in thesurface layer are replaced by C-F bonds and at the same time danglingbonds of Si present in the outermost surface are fluorinated (i.e., madeto combine with fluorine).

Comparison of this water repellency is carried out by the evaluationbased on contact angles measured when drops of pure water are placed onan evaluation sample. The greater the contact angle, the higher thewater repellency.

Meanwhile, when only the outermost surface of the surface layer isfluorinated, it has been found that, in the electrophotographicapparatus that successively repeats the steps of charging, exposure,development, transfer, separation and cleaning for performing scrapecleaning by means of a blade, the outermost surface of thelight-receiving member is abraded by a toner and an abrasive or the likecontained in the toner, so that the water repellency becomes ineffectiveas a result of such repeated operation. It was also attempted to usefluorine type gases so that fluorine atoms can be actively incorporatedinto the surface layer. When, however, a plasma processing apparatusmaking use of a high-frequency power is employed, it is not easy toincorporate fluorine atoms in the film as desired. Even if it waspossible to incorporate a desired content of fluorine atoms into thefilm, the film did not have a sufficient mechanical strength, and alsothe deposition must be carried out for a long time. Thus, there are somepoints to be more improved.

The present inventors made various studies on the above problems. As theresult, they have found that fluorine atoms can be incorporated into thesurface layer in a good efficiency and also in a desired content, andalso at an improved deposition rate, by repeating film formation andetching plural times as previously described.

They also have found that even when formation of the surface layer iscarried out by using starting gases containing no fluorine type gas, bypreviously coating a surface on which a deposited film is formed withfluorine atoms, reaction between fluorine atoms and carbon atoms occurson the surface during film formation to fully form a three-dimensionalnetwork of carbon atoms into which fluorine atoms are incorporated as aterminator. As this result, it is possible to incorporate fluorine atomsinto a film while having a sufficient mechanical strength and high waterrepellency at the same time. The deposition rate in this method is thesame as where in the case that the surface is not coated with fluorineatoms, and it is possible to form a film at a large rate sufficient forpractical use.

Also, in the electrophotographic apparatus that successively repeats thesteps of charging, exposure, development, transfer, separation andcleaning for performing scrape cleaning by means of a blade, a surfaceof the surface layer with a high water repellency which alwayscontaining fluorine can be obtained while maintaining the hardnessrequired as a surface protective layer and the initial frictionalresistance, even if the outermost surface of the surface layer on thelight-receiving layer has been abraded by a toner and an abrasive or thelike contained in the toner. According to the present invention,fluorine atoms can also be incorporated into the surface layer in a goodefficiency and also at a high density by forming the surface layerparticularly under application of the high-frequency power having adischarge frequency of from 50 MHz to 450 MHz. Hence, the presentinvention has the effect that the surface layer can achieve a superiorcleaning performance, cause no toner scatter and prevent wirecontamination. This effect also found when oxygen atoms or nitrogenatoms are present.

The present invention will be described below in detail with referenceto the accompanying drawings.

FIG. 1 is a diagrammatic cross section to show a surface layer providedwith a plurality of alternating regions comprising fluorine atomsdiffused therein and fluorine atoms combined therewith respectively, byalternately repeating the film formation and etching according to thepresent invention. In FIG. 1, reference numeral 101 denotes regions inwhich fluorine atoms have been introduced by etching and film formation,102 denotes regions where fluorine atoms are present in a combined stateby etching after film formation, and 100 denotes a layer formed forproducing a surface layer or a light-receiving layer comprising aphotoconductive layer. In the example shown in the drawing presentedhere, the surface layer 104 is composed of eight layers. The surfacelayer may be composed of any number of layers so long as they arecomposed of a plurality of layers, which usually may preferably bewithin the range of 4 to 50 layers. With regard to the outermostsurface, it is particularly preferred to be a film subjected to etching.The thickness of a film deposited by film formation carried out once maybe determined as desired, and may preferably be from 30 to 2,500 Å, andmore preferably from 60 to 1,000 Å. Also, the respective layers may beformed under conditions constant for all the layers or conditionschanged accordingly. For example, the respective layers may be formed inthe manner that carbon content increases toward the surface.

Fluorine atoms can be incorporated into the surface layer in thefollowing way: as in the formation of usual light-receiving layers, athin layer of amorphous silicon carbide (hereinafter referred to as"a-SiC") is deposited, and thereafter a fluorine type gas is introducedto subject its surface to etching to cause fluorine atoms to combinewith that surface. Next, a thin layer of a-SiC is again depositedthereon to form an a-SiC layer containing fluorine atoms utilizing thereaction of fluorine atoms on the surface of a lower deposited layerwith the upper deposited layer. Then, its surface is subjected toetching in the same manner as the foregoing. This operation is repeateduntil the surface layer has the desired thickness, whereby a pluralityof alternating regions comprising fluorine atoms contained therein andfluorine atoms combined therewith respectively can be formed. Thus, thesurface layer having high hardness and high water repellency can beobtained.

Fluorine atoms contained in the surface layer are non-uniformlydistributed in the layer thickness direction. Specifically, the surfacelayer has large content regions of fluorine atoms and small contentregions of fluorine atoms. For example, the surface layer has largecontent regions of fluorine atoms and a small content region interposedtherebetween. The surface layer may have a region containingsubstantially no fluorine atoms between the large content region and thesmall content region of fluorine atoms.

The layer removed by the etching may preferably have a depth from about20 to 2,000 Å, and more preferably from 50 to 500 Å.

The region with which fluorine atoms have combined may preferably be ina thickness from 1 to 500 Å, and more preferably from 10 to 50 Å.

As the fluorine type gas used in the etching, fluorine type gases suchas CF₄, CHF₃, CH₂ F₂, CH₃ F, C₂ F₆ and ClF₃ may preferably be used.

FIG. 2 diagrammatically illustrates an example of a deposition apparatusfor producing the light-receiving member by plasma-assisted CVDemploying a high-frequency power source according to the presentinvention.

Stated roughly, this apparatus is constituted of a deposition system2100, a starting gas feed system 2200 and an exhaust system (not shown)for reducing the internal pressure of a reactor 2110. In the reactor2110 in the deposition system 2100, a cylindrical substrate 2112 onwhich a film is formed and which is connected to a ground, a heater 2113for heating the cylindrical substrate 2112, and a starting gas feed pipe2114 are provided. A high-frequency power source 2120 is also connectedto the reactor via a high-frequency matching box 2115.

The starting gas feed system 2200 is constituted of gas cylinders 2221to 2226 for starting gases and etching gases, such as SiH₄, H₂, CH₄, NO,B₂ H₆ and CF₄, valves 2231 to 2236, 2241 to 2246 and 2251 to 2256, andmass flow controllers 2211 to 2216. The gas cylinders for the respectivecomponent gases are connected to the gas feed pipe 2114 in the reactor2110 through a valve 2260.

The high-frequency power source used in the formation of the surfacelayer in the present invention can be preferably used at a dischargefrequency within a range of from 50 MHz to 450 MHz. If a dischargefrequency higher than 450 MHz is used, the discharge stability anduniformity may become unsatisfactory and the discharge may be localized,so that the deposited films may have non-uniform layer thickness. Theoutput power of the power source may be preferably within the range offrom 10 W to 5,000 W, and there are no particular limitations on therange of output power so long as an electric power suitable for theapparatus used can be generated. With regard to the degree of outputvariability, there are also no particular limitations on its value solong as the desired films can be formed.

The cylindrical substrate 2112 is placed on a conductive pedestal 2123,where it is connected to a ground. Cathode electrodes 2111 are comprisedof a conductive material, and are insulated with insulating materials2121. As conductive materials used in the conductive pedestal 2123,copper, aluminum, gold, silver, platinum, lead, nickel, cobalt, iron,chromium, molybdenum, titanium, stainless steel, and composite materialsof two or more of these may be used.

As the insulating materials for insulating the cathode electrodes 2111,insulating materials such as ceramics, Teflon, mica, glass, quartz,silicone rubber, polyethylene and polypropylene may be used.

As the high-frequency matching box 2115, those having any constitutioncan be preferably used so long as they can allow matching between thehigh-frequency power source 2120 and load. As methods for the matching,it may preferably be automatically controlled, or may be manuallycontrolled without any adverse effect on the present invention.

As materials for the cathode electrodes 2111 to which the high-frequencypower is to be applied, copper, aluminum, gold, silver, platinum, lead,nickel, cobalt, iron, chromium, molybdenum, titanium, stainless steel,and composite materials of two or more of these materials may be used.The cathode electrodes may preferably have a cylindrical shape, and mayoptionally have an ellipsoidal shape or a polygonal shape.

The cathode electrodes 2111 may be optionally provided with a coolingmeans. As a specific cooling means, the electrodes may be cooled withwater, liquid nitrogen, Peltier devices or the like, which may beselected as occasion calls. In FIG. 2, an example is shown in which aninsulating shield plate is provided around the reactor 2110.

The cylindrical substrate 2112 may be made of any material and may haveany shape in accordance with its uses. For example, with regard to itsshape, it may preferably be cylindrical when electrophotographicphotosensitive members are produced, or may optionally have the shape ofa flat plate or any other shape. With regard to its material, copper,aluminum, gold, silver, platinum, lead, nickel, cobalt, iron, chromium,molybdenum, titanium, stainless steel, and composite materials of two ormore of these materials, as well as insulating materials such aspolyester, polyethylene, polycarbonate, cellulose acetate,polypropylene, polyvinyl chloride, polyvinylidene chloride, polystyrene,glass, quartz, ceramics and paper which are coated with conductivematerials may be used.

An example of the procedure for the formation of the light-receivingmember will be described with reference to the apparatus shown in FIG.2.

The cylindrical substrate 2112 is set in the reactor 2110, and theinside of the reactor 2110 is evacuated by means of an exhaust device(not shown; e.g., a vacuum pump). Subsequently, the temperature of thecylindrical substrate 2112 is controlled at a desired temperature of,e.g., from 20° C. to 500° C. by means of the heater 2113 for heating thecylindrical substrate. Next, before material gases for forming thelight-receiving member are flowed into the reactor 2110, gas cylindervalves 2231 to 2236 and a leak valve 2117 of the reactor are checked tomake sure that they are closed, and also flow-in valves 2241 to 2246,flow-out valves 2251 to 2256 and an auxiliary valve 2260 are checked tomake sure that they are opened. Then, a main valve 2118 is opened toevacuate the insides of the reactor 2110 and a gas feed pipe 2116.

Thereafter, at the time a vacuum gauge 2119 has been read to indicate apressure of about 5×10⁻⁶ Torr, the auxiliary valve 2260 and the flow-outvalves 2251 to 2256 are closed. Thereafter, gas cylinder valves 2231 to2236 are opened so that gases are respectively introduced from gascylinders 2221 to 2226, and each gas is controlled to have a pressure of2 kg/cm² by operating pressure controllers 2261 to 2266. Next, theflow-in valves 2241 to 2246 are gradually opened so that gases arerespectively introduced into mass flow controllers 2211 to 2216.

After film formation is thus ready to start through the above procedure,a photoconductive layer is first formed on the cylindrical substrate2112.

More specifically, at the time the cylindrical substrate 2112 has had adesired temperature, some necessary flow-out valves among the valves2251 to 2256 and the auxiliary valve 2260 are gradually opened so thatdesired starting gases are fed into the reactor 2110 from the gascylinders 2221 to 2226 through a gas feed pipe 2114. Next, the mass flowcontrollers 2211 to 2216 are operated so that each starting gas isadjusted to flow at a desired rate. In that course, the divergence ofthe main valve 2118 is so adjusted that the pressure inside the reactor2110 becomes a desired pressure of not higher than 1 Torr, whilewatching the vacuum gauge 2119. At the time the inner pressure hasbecome stable, a high-frequency power source 2120 is set at a desiredelectric power, and a high-frequency power with a frequency of from 1MHz to 450 MHz is supplied to the cathode electrode 2111 through thehigh-frequency matching box 2115 to generate high-frequency glowdischarge. The starting gases fed into the reactor 2110 are decomposedby the discharge energy thus produced, so that a desired photoconductivelayer mainly composed of silicon atoms is deposited on the cylindricalsubstrate 2112. After a film with a desired thickness has been formed,the supply of high-frequency power is stopped, and the flow-out valves2251 to 2256 are closed to stop starting gases from flowing into thereactor 2110. The formation of the photoconductive layer is thuscompleted.

The composition and layer thickness of a light-receiving layercomprising a photoconductive layer may be selected as conventionallydone.

The light-receiving layer comprising a photoconductive layer and acharge injection blocking layer may be formed by non-single-crystallinematerials. Specifically, an amorphous material (which also includesmicrocrystal), a polycrystalline material and their combination may beused. These materials preferably contain silicon atoms or germaniumatoms. If necessary, they may contain an element capable of controllinga conductivity type such as boron, arsenic and phosphorus as well as atleast one kind element of carbon, oxygen or nitrogen. These elements maybe distributed uniformly or non-uniformly, and the distribution and thecontents of these elements are determined depending on desiredcharacteristics.

The surface layer preferably contains carbon and, for example, it may berepresented by a-Si_(x) C_(1-x) (0≦×<1).

When the surface layer is formed on the photoconductive layer, basicallythe above operation may be repeated. Namely, film forming gases andetching gases may be alternately fed.

Stated specifically, some necessary flow-out valves among the valves2251 to 2256 and the auxiliary valve 2260 are gradually opened so thatstarting gases necessary for the surface layer are fed into the reactor2110 from the gas cylinders 2221 to 2226 through a gas feed pipe 2114.

Next, the mass flow controllers 2211 to 2216 are operated so that eachstarting gas is adjusted to flow at a desired rate. In that course, thedivergence of the main valve 2118 is so adjusted that the pressureinside the reactor 2110 comes to be a desired pressure of not higherthan 1 Torr, while watching the vacuum gauge 2119. At the time the innerpressure has become stable, a high-frequency power source 2120 is set ata desired electric power, and a high-frequency power with a frequencywithin the range of from 50 MHz to 450 MHz is supplied to the cathodeelectrode 2111 through the high-frequency matching box 2115 to generatehigh-frequency glow discharge. The starting gases fed into the reactor2110 are decomposed by the discharge energy thus produced, so that ana-SiC deposited film is formed. After a film with a desired thicknesshas been formed, the supply of high-frequency power is stopped, and theflow-out valves 2251 to 2256 are closed to stop starting gases fromflowing into the reactor 2110. The formation of the deposited film isthus completed.

Next, some necessary flow-out valves among the valves 2251 to 2256 andthe auxiliary valve 2260 are gradually opened so that a fluorine typegas necessary for the etching is fed into the reactor 2110 from the gascylinders 2221 to 2226 through a gas feed pipe 2114. Next, the mass flowcontrollers 2211 to 2216 are operated so that the fluorine type gas isadjusted to flow at a desired rate. In that course, the divergence ofthe main valve 2118 is so adjusted that the pressure inside the reactor2110 comes to be a desired pressure of not higher than 1 Torr, whilewatching the vacuum gauge 2119. At the time the inner pressure hasbecome stable, a high-frequency power source 2120 is set at a desiredelectric power, and a high-frequency power with a frequency within therange of from 50 MHz to 450 MHz is supplied to the cathode electrode2111 through the high-frequency matching box 2115 to generatehigh-frequency glow discharge. The fluorine type gas fed into thereactor 2110 is decomposed by the discharge energy thus produced andreacts with the above deposited film, so that the etching treatment ofthe deposited film is carried out. After the etching treatment of thedeposited film in a desired depth, the supply of high-frequency power isstopped, and the flow-out valves 2251 to 2256 are closed to stop thefluorine type gas from flowing into the reactor 2110. The etchingtreatment of the deposited film is thus completed. The previousoperation for the film formation and this operation for the etching arealternately repeated until a desired layer thickness is obtained. Thus,the surface layer is formed.

When the film forming gases and the fluorine type gas are changed foreach other, the gas or gases remaining inside the reactor 2110 may bepurged every time. More preferably, from the viewpoint of film adhesion,the flow rates at the mass flow controllers may be alternatelycontrolled without purging the reactor and, with regard to the dischargealso, the discharge may be continuously carried out without stopping thedischarge every time.

While the film formation is carried out, the cylindrical substrate 2112may be rotated at a desired speed by driving means (not shown).

The deposited films formed by this apparatus is exemplified by an a-Sitype photosensitive member. A cross section of a typical a-Si typephotosensitive member is diagrammatically shown in FIGS. 3A and 3B.

FIG. 3A illustrates a single-layer type photosensitive member comprisinga photoconductive layer 303 formed of a single layer not functionallyseparated. FIG. 3B illustrates an example of a function-separatedphotosensitive member comprising a photoconductive layer 303 separatedinto a charge generation layer 305 and a charge transport layer 306.

The a-Si type light-receiving member shown in FIG. 3A has a conductivesubstrate 301 made of aluminum or the like, and a charge injectionblocking layer 302, a photoconductive layer 303 and a surface layer 304which are superposingly formed on the surface of the conductivesubstrate 301 in this order. Here, the charge injection blocking layer302 is formed to block the injection of charges from the conductivesubstrate 301 into the photoconductive layer 303, and is optionallyprovided. The photoconductive layer 303 is formed of anon-single-crystalline material, preferably an amorphous material,containing at least silicon atoms and exhibiting photoconductivity.Also, the surface layer 304 contains at least carbon atoms, hydrogenatoms and fluorine atoms and is produced by the process as mentionedabove, and has the ability to bear latent images formed in theelectrophotographic apparatus. In the following description, the chargeinjection blocking layer 302 is regarded as being provided, except forthe case when an effect differs depending on whether or not the chargeinjection blocking layer 302 is provided. The function of the chargeinjection blocking layer 302 may be incorporated into thephotoconductive layer 303.

The a-Si type light-receiving member shown in FIG. 3B is of afunction-separated type wherein the photoconductive layer 303 isconstituted of a charge transport layer 306 formed of anon-single-crystalline material, preferably an amorphous material,containing at least silicon atoms and carbon atoms, and a chargegeneration layer 305 formed of an amorphous material containing at leastsilicon atoms, which are formed in this order. Upon exposure of thislight-receiving member to light, carriers mainly produced in the chargegeneration layer 305 reach the conductive substrate 301 through thecharge transport layer 306. Incidentally, the charge generation layer305 and the charge transport layer 306 may be provided in the orderreverse to that in FIG. 3B, i.e., the charge generation layer 305 may beprovided on the side of the conductive substrate 301.

FIG. 4 schematically illustrates an example of an electrophotographicapparatus, for describing an example of an image forming method embodiedby the electrophotographic apparatus. A light-receiving member 401 isset temperature-controllable by means of a face heater 423 providedalong the inside of the light-receiving member 401, and is rotated inthe direction of an arrow X as necessary. Around the light-receivingmember 401, a primary corona assembly 402, an electrostatic latent imageforming portion 403, a developing assembly 404, a transfer medium feedsystem 405, a transfer corona assembly 406(a), a separation coronaassembly 406(b), a cleaner 450, a transport system 408, a chargeelimination light source 409 and so forth are provided as necessary.

An example of the image forming method will be more specificallydescribed below. The light-receiving member 401 is uniformlyelectrostatically charged by means of the primary corona assembly 402,to which a high voltage of +6 to +8 kV is applied. Light emitted from alamp 410 reflects from an original 412 placed on an original glass plate411 and passes through mirrors 413, 414 and 415, and an image is formedthrough a lens 418 of a lens unit 417 and is then guided through amirror 416 and projected into the electrostatic latent image formingportion as light that carries information, so that an electrostaticlatent image is formed on the light-receiving member 401. To this latentimage, a toner with a negative polarity is fed from the developingassembly 404. This exposure may be carried out not using the lightreflected from the original 412 but using an LED array, a laser beam, aliquid crystal shutter array or the like so that the light that carriesinformation is scanned to carry out scanning exposure.

Meanwhile, a transfer medium (or a recording medium) P such as paper ispassed through a transfer medium feed system 405 and is fed in thedirection of the light-receiving member 401 while adjusting its leadingpart feed timing by means of resist rollers 422. A positive electricfield, having a polarity reverse to that of the toner, is imparted tothe transfer medium P on the back thereof at the gap between thetransfer corona assembly 406(a), to which a high voltage of +6 to +8 kVis applied, and the surface of the light-receiving member 401. As theresult, the negative-polarity toner image formed on the surface of thelight-receiving member is transferred to the transfer medium P. Next, itis separated from the light-receiving member 401 by means of theseparation corona assembly 406(b), to which an AC voltage with a highvoltage of 12 to 14 kVpp and 300 to 600 Hz. Subsequently, the transfermedium P is passed through the transfer medium transport system 408 toreach a fixing assembly 424, where the toner image is fixed, and thetransfer medium P with the fixed image is delivered out of theapparatus.

The toner remaining on the light-receiving member 401 is collected by acleaning roller 407 and a cleaning blade 421 made of an elastic materialsuch as silicone rubber or urethane rubber which are provided in acleaner 450, and the remaining electrostatic latent image is erased byexposure to light from the charge elimination light source 409.

Incidentally, reference numeral 420 denotes a blank exposure LEDprovided In order to optionally expose the light-receiving member 401 tolight so that a toner may not adhere to the non-image area of thelight-receiving member 401 at its portion extending beyond the width ofthe transfer medium P.

FIGS. 5, 6 and 7 are diagrammatic views to illustrate an example of anapparatus (a mass production type) for producing light-receiving membersby VHF plasma-assisted CVD, having a form different from the apparatusshown in FIG. 2. FIG. 7 diagrammatically illustrates the wholeconstruction of the present apparatus. FIG. 5 diagrammaticallyillustrates a vertical cross section at the part of its reactor. FIG. 6diagrammatically illustrates a transverse cross section at the part ofits reactor.

In FIGS. 5 to 7, reference numeral 5100 denotes a deposition system,which is so made up that it can be kept in an atmosphere of a reducedpressure. Reference numeral 5113 denotes an exhaust tube that opens tothe inside of a reactor 5111 and communicates with an exhaust system(not shown) at the other end thereof. Reference numeral 5130 denotes adischarge space surrounded by a plurality of cylindrical conductivesubstrates 5115. A high-frequency power source 5119 is electricallyconnected to a cathode electrode 5118 via a high-frequency matching box5112. The cylindrical conductive substrates 5115 are each providedaround a rotating shaft 5114, being set on a pedestal 5121. A startinggas feed system 5200 has gas cylinders 5221 to 5226 in which startinggases and etching gases, such as SiH₄, H₂, CH₄, N₂, B₂ H₆ and CF₄, arerespectively enclosed, valves 5231 to 5236, 5241 to 5246 and 5251 to5256, and mass flow controllers 5211 to 5216. The gas cylinders for therespective starting gases are connected to the gas feed pipe 5117 in thereactor 5111 through a valve 5260.

As the high-frequency power source used in the present invention, anypower source may be used so long as it can output a power having afrequency within the range of from 50 MHz to 450 MHz as the dischargefrequency at least for the formation of the surface layer. Of course, inorder to form other layers (or regions), it is preferable to control thepower source so that it can output a power having a frequency within arange different from that for the formation of the surface layer, or tofurther provide an additional power source so that it can output such apower. As for the output power, a power source having any output powermay be used so long as it can produce an output power suited for theapparatus used at an output power within the range of from 10 W to 5,000W.

With regard to the degree of output variability, there are also noparticular limitations thereon.

As the high-frequency matching box 5112, those having any constitutioncan be preferably used so long as they can make matching between thehigh-frequency power source 5119 and load. As methods for the matching,it may preferably be automatically controlled, or may be manuallycontrolled without any adverse effect on the present invention.

As materials for the cathode electrode 5118 to which the high-frequencypower is to be applied, copper, aluminum, gold, silver, platinum, lead,nickel, cobalt, iron, chromium, molybdenum, titanium, stainless steel,and composite materials of two or more of these materials may be used.The cathode electrode may preferably have a cylindrical shape, and mayoptionally have an ellipsoidal shape or a polygonal shape. The cathodeelectrode 5118 may be optionally provided with a cooling means. As aspecific cooling means, the electrode may be cooled with water, liquidnitrogen, Peltier devices or the like, which may be selected as occasioncalls.

The cylindrical conductive substrates 5115 may be made of any materialand may have any shape in accordance with its uses. For example, withregard to the shape, they may preferably be cylindrical whenelectrophotographic photosensitive members are produced, or mayoptionally have the shape of a flat plate or any other shape. Withregard to its material, copper, aluminum, gold, silver, platinum, lead,nickel, cobalt, iron, chromium, molybdenum, titanium, stainless steel,and composite materials of two or more of these materials, as well asinsulating materials such as polyester, polyethylene, polycarbonate,cellulose acetate, polypropylene, polyvinyl chloride, polyvinylidenechloride, polystyrene, glass, quartz, ceramics and paper which arecoated with conductive materials may be used.

The present invention will be described below in greater detail bygiving Experimental Examples. The present invention is by no meanslimited by these.

EXPERIMENTAL EXAMPLE 1

Light-receiving members were produced under the conditions as shown inTable 1 using the plasma-assisted CVD apparatus shown in FIG. 2. Thesurface layer was formed by superposingly forming deposited films oneafter another while repeating film formation and etching. Here,formation of the deposited film having a film thickness of 1,000 Å underconditions as shown in Table 1 and the etching treatment of thedeposited film having a thickness of 1,000 Å for etching in a depth of500 Å under conditions as shown in Table 2 were repeated to form asurface layer containing fluorine atoms and having a layer thickness of3,000 Å in total. As fluorine sources, CF₄, CHF₃ and ClF₃ wererespectively used so that three light-receiving members were produced,corresponding to the three kinds of fluorine sources.

To evaluate the water repellency of the above three light-receivingmembers, the contact angles of their surfaces with respect to pure waterwere measured using a contact angle meter. As a result, all thelight-receiving members showed a contact angle of 100 degrees orgreater, having achieved a high water repellency. Then, these threelight-receiving members were each mounted on a copying machine, andcontinuous paper feed running on 1,000,000 sheets of A4-size white paperwas tested in an environment of high temperature and high humidity of30° C. and 80% RH to make evaluation on smeared images. In this test,the steps of charging, exposure, development, transfer, separation andscrape cleaning were repeated in order, without using any heating meansfor the light-receiving member.

The results obtained in the above evaluation are shown in Table 3.

As is seen from the results, in the 1,000,000 sheets running, all thelight-receiving members did not cause faulty images such as smearedimages and stains at all. After the 1,000,000 sheets running, thecontact angle was again measured. As the result, it was 100 degrees orgreater in all the light-receiving members, finding that, as for gasspecies used in the etching, it was possible to maintain the initialwater repellency when any fluorine type gases were used. Evaluation wasalso made on the contamination of the corona assembly wire during therunning, which was evaluated on the basis of uneven halftone imagedensity.

(Halftone Evaluation)

A method for the evaluation on uneven halftone image density will bedescribed below with reference to FIG. 4.

The amount of charge electric current of the primary charging assembly402 was so controlled that the dark portion potential at the position ofthe developing assembly 404 was 400 V. An original 412 with a reflectiondensity of 0.3 was placed on the original glass plate 411, and thelighting voltage of the halogen lamp 410 was so controlled that thelight portion potential was 200 V, where A3-size halftone images wereformed. Using the images thus formed, any uneven density in lines causedby the wire contamination was observed.

The results obtained in the above evaluation are shown in Table 4.

In the 1,000,000 sheets running, all the light-receiving members causedno uneven density in lines due to wire contamination. It has been foundfrom this result that, as for gas species used in the etching, it waspossible to maintain the initial water repellency when any fluorine typegases were used.

EXPERIMENTAL EXAMPLE 2

Light-receiving members were produced using the plasma-assisted CVDapparatus shown in FIG. 2, under conditions as shown in Table 1. Whenthe surface layer was formed, a deposited film with a film thickness of3,500 Å was formed at one time. The deposited film thus formed wassubjected to etching by fluorine treatment on only the outermost surfaceunder conditions as shown in Table 2, and the deposited film was etchedin a depth of 500 A so that the surface layer finally had a thickness of3,000 Å.

As fluorine sources, CF₄, CHF₃ and ClF₃ were respectively used so thatthree light-receiving members were produced, corresponding to the threekinds of fluorine sources.

To evaluate the water repellency of the above three light-receivingmembers, the contact angles of their surfaces with respect to pure waterwere measured in the same manner as in Experimental Example 1. As aresult, all the light-receiving members showed a contact angle of 100degrees or greater, having achieved a high water repellency.

Then, these three light-receiving members were tested in the same manneras in Experimental Example 1 by continuous paper feed running on A4-size1,000,000 sheets in an environment of high temperature and high humidityof 30° C. and 80% RH to make evaluation on smeared images. In this test,like Experimental Example 1, the steps of charging, exposure,development, transfer, separation and scrape cleaning were repeated inorder, without using any heating means for the light-receiving member.

The results obtained in the above evaluation are shown in Table 3.

As is seen from the results, in the 1,000,000 sheets running, all thelight-receiving members caused smeared images on the 500,000th sheet andthereafter in some cases.

After the 1,000,000 sheets running, the contact angle of eachlight-receiving member was again measured. As the result, it was at thevalue of 50 degrees or less in all the light-receiving members.

Evaluation was also made on the contamination of the corona assemblywire during the running, which was evaluated on the basis of unevenhalftone image density in the same manner as in Experimental Example 1.

The results obtained in the above evaluation are shown in Table 4.

As is seen from the results, in the 1,000,000 sheets running, the unevendensity in lines caused by the wire contamination in all thelight-receiving members was on the level of no problem in practical use.

                  TABLE 1    ______________________________________    Conditions for Production of Light-receiving Member    ______________________________________    Lower blocking layer    SiH.sub.4           300 SCCM    H.sub.2             500 SCCM    NO                  8 SCCM    B.sub.2 H.sub.6     2,000 ppm    Power               100 W (105 MHz)    Internal pressure   20 mTorr    Layer thickness     1 μm    Photoconductive layer    SiH.sub.4           500 SCCM    H.sub.2             500 SCCM    Power               400 W (105 MHz)    Internal pressure   20 mTorr    Layer thickness     20 μm    Surface layer    SiH.sub.4           50 SCCM    CH.sub.4            500 SCCM    Power               100 W (105 MHz)    Internal pressure   20 mTorr    Layer thickness     0.3 μm    ______________________________________

                  TABLE 2    ______________________________________    Conditions for Fluorine Treatment    ______________________________________    CF.sub.4            500 SCCM    Substrate temperature                        250° C.    Pressure            20 mTorr    Power               500 W (105 MHz)    Etching depth       0.05 μm    ______________________________________

                  TABLE 3    ______________________________________    Initial   1 × 10.sup.5                       3 × 10.sup.5                               5 × 10.sup.5                                      8 × 10.sup.5                                            1 × 10.sup.6    stage     sheets   sheets  sheets sheets                                            sheets    ______________________________________    Experimental Example 1:    CF.sub.4          A       A        A     A      A     A    CHF.sub.3          A       A        A     A      A     A    ClF.sub.3          A       A        A     A      A     A    Experimental Example 2:    CF.sub.4          A       A        A     B      C     C    CHF.sub.3          A       A        A     B      C     C    ClF.sub.3          A       A        A     B      C     C    ______________________________________     A: No smeared images.     B: Smeared images partly occur in some cases.     C: Smeared images occur over the whole area in some cases.

                  TABLE 4    ______________________________________    Initial   1 × 10.sup.5                       3 × 10.sup.5                               5 × 10.sup.5                                      8 × 10.sup.5                                            1 × 10.sup.6    stage     sheets   sheets  sheets sheets                                            sheets    ______________________________________    Experimental Example 1:    CF.sub.4          AA      AA       AA    AA     AA    AA    CHF.sub.3          AA      AA       AA    AA     AA    AA    ClF.sub.3          AA      AA       AA    AA     AA    AA    Experimental Example 1:    CF.sub.4          AA      AA       AA    A      A     B    CHF.sub.3          AA      AA       AA    A      A     B    ClF.sub.3          AA      AA       AA    A      A     B    ______________________________________     Uneven halftone image density:     AA: Very well free of uneven density.     A: Well free of uneven density.     B: Uneven density partly occur (no problem in practical use).     C: Uneven density in lines occur over the whole area of images in some     cases.

EXPERIMENTAL EXAMPLE 3

Light-receiving members were produced in the same manner as inExperimental Example 1 while repeating the film formation and etching toform the surface layer having a layer thickness of 3,000 Å in total,except that, in the formation of the surface layer, the thickness ofdeposited films and the etching depth by etching treatment were variedin five ways as shown in Table 5 below. CF₄ gas was used as the fluorinesource.

                  TABLE 5    ______________________________________    Deposited film                  Etching depth                             Light-receiving    thickness (Å)                  (Å)    member    ______________________________________    520            20        (A)    550            50        (B)    600           100        (C)    1,000         500        (D)    1,500         1,000      (E)    ______________________________________

To evaluate the water repellency of the above five light-receivingmembers (A) to (E), the contact angles of their surfaces with respect topure water were measured in the same manner as in ExperimentalExample 1. As a result, all the light-receiving members showed a contactangle of 100 degrees or greater, having achieved a high waterrepellency.

Next, these five light-receiving members were tested in the same manneras in Experimental Example 1 by continuous paper feed running on A4-size1,000,000 sheets in an environment of high temperature and high humidityof 30° C. and 80% RH to make evaluation on smeared images. In this test,like Experimental Example 1, the respective steps were repeated withoutusing any heating means for the light-receiving member.

The results obtained in the above evaluation are shown in Table 6.

As is seen from the results, in the 1,000,000 sheets running, all thelight-receiving members did not cause faulty images such as smearedimages and stains at all. After the 1,000,000 sheets running, thecontact angle was again measured. As the result, it was 100 degrees orgreater in all the light-receiving members, finding that it was possibleto maintain the initial water repellency so long as the etching for eachtime was in a depth of at least 20 Å.

Evaluation was also made on wire contamination of the corona assemblyduring the running, which was evaluated on the basis of uneven halftoneimage density in the same manner as in Experimental Example 1.

The results obtained in the above evaluation are shown in Table 7.

In the 1,000,000 sheets running, all the light-receiving members causedno uneven density in lines due to wire contamination. It has been foundfrom this result that it was possible to maintain the initial waterrepellency so long as the etching for each time was in a depth of atleast 20 Å.

EXPERIMENTAL EXAMPLE 4

A light-receiving members was produced using the plasma-assisted CVDapparatus shown in FIG. 2, under conditions as shown in Table 1. Here,the surface layer was formed by continuously forming the deposited filmwithout inserting the step of etching, to have a layer thickness of3,000 Å.

To evaluate the water repellency of the above light-receiving member,the contact angle of its surface with respect to pure water was measuredin the same manner as in Experimental Example 1. As a result, thecontact angle was 80 degrees.

Next, this light-receiving member was tested in the same manner as inExperimental Example 1 by continuous paper feed running on A4-size1,000,000 sheets in an environment of high temperature and high humidityof 30° C. and 80% RH to make evaluation on smeared images. In this test,like Experimental Example 1, the respective steps were repeated withoutusing any heating means for the light-receiving member.

The results obtained in the above evaluation are shown in Table 6.

As is seen from the results, in the 1,000,000 sheets running, thelight-receiving member caused smeared images on the 100,000th sheet andthereafter. After the 1,000,000 sheets running, the contact angle of thelight-receiving member was again measured. As the result, it was at thevalue of 20 degrees or less, confirming that it was impossible for thesurface layer containing no fluorine atoms to maintain the initial waterrepellency.

Evaluation was also made on wire contamination of the corona assemblyduring the running, which was evaluated on the basis of uneven halftoneimage density in the same manner as in Experimental Example 1.

The results obtained in the above evaluation are shown in Table 7. As isseen from the results, in the 1,000,000 sheets running, the unevendensity in lines caused by wire contamination was on the level of noproblem in practical use.

                  TABLE 6    ______________________________________    Initial  1 × 10.sup.5                     3 × 10.sup.5                              5 × 10.sup.5                                     8 × 10.sup.5                                            1 × 10.sup.6    stage    sheets  sheets   sheets sheets sheets    ______________________________________    Experimental Example 3:    (A)  A       A       A      A      A      A    (B)  A       A       A      A      A      A    (C)  A       A       A      A      A      A    (D)  A       A       A      A      A      A    (E)  A       A       A      A      A      A    Experimental Example 4:    A        B       B        C      C      C    ______________________________________     A: No smeared images.     B: Smeared images partly occur in some cases.     C: Smeared images occur over the whole area in some cases.

                  TABLE 7    ______________________________________    Initial  1 × 10.sup.5                     3 × 10.sup.5                              5 × 10.sup.5                                     8 × 10.sup.5                                            1 × 10.sup.6    stage    sheets  sheets   sheets sheets sheets    ______________________________________    Experimental Example 3:    (A)  AA      AA      AA     AA     AA     AA    (B)  AA      AA      AA     AA     AA     AA    (C)  AA      AA      AA     AA     AA     AA    (D)  AA      AA      AA     AA     AA     AA    (E)  AA      AA      AA     AA     AA     AA    Experimental Example 2:    AA       AA      A        A      A      B    ______________________________________     Uneven halftone image density:     AA: Very well free of uneven density.     A: Well free of uneven density.     B: Uneven density partly occur (no problem in practical use).     C: Uneven density in lines occur over the whole area of images in some     cases.

EXPERIMENTAL EXAMPLE 5

Light-receiving members were produced in the same manner as inExperimental Example 1 while repeating film formation and etching toform the surface layer having a layer thickness of 4,000 Å in total,except that the thickness of deposited films and the etching depth byetching treatment were varied in six ways as shown in Table 8 below. CF₄gas was used as the fluorine source.

                  TABLE 8    ______________________________________    Deposited film                  Etching depth                             Light-receiving    thickness (Å)                  (Å)    member    ______________________________________      520         500        (F)      550         500        (G)      600         500        (H)    1,000         500        (I)    1,500         500        (J)    2,500         500        (K)    ______________________________________

To evaluate the water repellency of the above six light-receivingmembers (F) to (K), the contact angles of their surfaces with respect topure water were measured in the same manner as in ExperimentalExample 1. As a result, all the light-receiving members showed a contactangle of 100 degrees or greater, having achieved a high waterrepellency.

Next, these six light-receiving members were tested in the same manneras in Experimental Example 1 by continuous paper feed running on A4-size1,000,000 sheets in an environment of high temperature and high humidityof 30° C. and 80% RH to make evaluation on smeared images. In this test,like Experimental Example 1, the respective steps were repeated withoutusing any heating means for the light-receiving member.

The results obtained in the above evaluation are shown in Table 9.

As is seen from the results, in the 1,000,000 sheets running, all thelight-receiving members did not cause faulty images such as smearedimages at all. After the 1,000,000 sheets running, the contact angle wasagain measured. As the result, it was 100 degrees or greater in thelight-receiving members other than (K), finding that it was possible tomaintain the initial water repellency. With regard to thelight-receiving member (K), however, the contact angle was 75 degreesafter 500,000 sheet running. All the light-receiving members caused nofaulty images such as stains.

Evaluation was also made on the wire contamination of the coronaassembly during the running, which was evaluated on the basis of unevenhalftone image density in the same manner as in Experimental Example 1.

The results obtained in the above evaluation are shown in Table 10.

As is seen from the results, in the 1,000,000 sheets running, all thelight-receiving members caused no uneven density in lines due to wirecontamination.

It has been found from the foregoing results that in formation of thesurface layer comprising deposited films formed by repeating filmformation and etching, a thickness of each deposited film preferably isnot larger than 2,500 Å. If each thickness of the deposited films issmaller than 30 Å, the deposited film may have an insufficientuniformity, or the total surface layer formation takes a longer timebecause of an increase in the number of etching times.

                  TABLE 9    ______________________________________    Initial   1 × 10.sup.5                       3 × 10.sup.5                               5 × 10.sup.5                                      8 × 10.sup.5                                            1 × 10.sup.6    stage     sheets   sheets  sheets sheets                                            sheets    ______________________________________    Experimental Example 5:    (F)   A       A        A     A      A     A    (G)   A       A        A     A      A     A    (H)   A       A        A     A      A     A    (I)   A       A        A     A      A     A    (J)   A       A        A     A      A     A    (K)   A       A        A     B      B     B    Experimental Example 6:    (F")  A       A        A     A      A     A    (G')  A       A        A     A      A     A    (H')  A       A        A     A      A     A    (I')  A       A        A     A      A     A    (J')  A       A        A     A      A     A    (K')  A       A        A     B      B     C    ______________________________________     A: No smeared images.     B: Smeared images partly occur in some cases.     C: Smeared images occur over the whole area in some cases.

                  TABLE 10    ______________________________________    Initial   1 × 10.sup.5                       3 × 10.sup.5                               5 × 10.sup.5                                      8 × 10.sup.5                                            1 × 10.sup.6    stage     sheets   sheets  sheets sheets                                            sheets    ______________________________________    Experimental Example 5:    (F)   AA      AA       AA    AA     AA    AA    (G)   AA      AA       AA    AA     AA    AA    (H)   AA      AA       AA    AA     AA    AA    (I)   AA      AA       AA    AA     AA    AA    (J)   AA      AA       AA    AA     AA    AA    (K)   AA      AA       AA    A      A     A    Experimental Example 6:    (F')  A       A        A     A      A     B    (G')  A       A        A     A      A     B    (H')  A       A        A     A      A     B    (I')  A       A        A     A      A     B    (J')  A       A        A     A      A     B    (K')  A       A        A     A      B     B    ______________________________________     Uneven halftone image density:     AA: Very well free of uneven density.     A: Well free of uneven density.     B: Uneven density partly occur (no problem in practical use).     C: Uneven density in lines occur over the whole area of images in some     cases.

EXPERIMENTAL EXAMPLE 6

Light-receiving members were produced in the same manner as inExperimental Example 1 while repeating the film formation and etching toform the surface layer having a layer thickness of 4,000 Å in total,except that the surface layer was formed using a high-frequency power of13.5 MHz under conditions as shown in Table 11 below and the depositedfilms were formed, and etched by fluorine treatment, while the filmthickness and the etching depth were varied in six ways as shown inTable 12 below. CF₄ gas was used as the fluorine source.

                  TABLE 11    ______________________________________    Surface layer    SiH.sub.4            50 SCCM    CH.sub.4             500 SCCM    Power                100 W (13.56 MHz)    Internal pressure    0.4 Torr    Fluorine treatment conditions    CF.sub.4             500 SCCM    Substrate temp.      250° C.    Pressure             0.4 Torr    Power                500 W (13.56 MHz)    ______________________________________

                  TABLE 12    ______________________________________    Deposited film                  Etching depth                             Light-receiving    thickness (Å)                  (Å)    member    ______________________________________      520         500        (F')      550         500        (G')      600         500        (H')    1,000         500        (I')    1,500         500        (J')    2,500         500        (K')    ______________________________________

To evaluate the water repellency of the above six light-receivingmembers (F') to (K'), the contact angles of their surfaces with respectto pure water were measured in the same manner as in ExperimentalExample 1. As a result, all the light-receiving members showed a contactangle of 100 degrees or greater, having achieved a high waterrepellency.

Next, these six light-receiving members were tested in the same manneras in Experimental Example 1 by continuous paper feed running on A4-size1,000,000 sheets in an environment of high temperature and high humidityof 30° C. and 80% RH to make evaluation on smeared images. In this test,like Experimental Example 1, the respective steps were repeated withoutusing any heating means for the light-receiving member.

The results obtained in the above evaluation are shown in Table 9.

As is seen from the results, in the 1,000,000 sheets running, all thelight-receiving members other than (K') caused no faulty images such assmeared images at all. After the 1,000,000 sheets running, the contactangle was again measured. As the result, it was 75 degrees or greater inthe light-receiving members other than (K'), finding that it waspossible to maintain a water repellency endurable to practical use. Withregard to the light-receiving member (K'), however, the contact anglewas 50 degrees after 1,000,000 sheets running. All the light-receivingmembers caused no faulty images such as stains.

Evaluation was also made on the wire contamination of the coronaassembly during the running, which was evaluated on the basis of unevenhalftone image density in the same manner as in Experimental Example 1.

The results obtained in the above evaluation are shown in Table 10.

As is seen from Table 10, in the 1,000,000 sheets running, the unevendensity in lines caused by wire contamination was on the level of noproblem in practical use. However, all the light-receiving members ofExperimental Example 6 were found to have caused uneven density in partwhen the 1,000,000 sheets running was finished.

It has been found from the foregoing results that, when thehigh-frequency power source used in the formation of the surface layeris used at a frequency of from 50 MHz to 450 MHz, the structure of filmscan be made more dense, the fluorine atoms can be incorporated in animproved efficiency, and the cleaning performance can be more improvedthan the conventional cases.

EXPERIMENTAL EXAMPLE 7

Light-receiving members were produced using the plasma-assisted CVDapparatus shown in FIG. 2, under conditions as shown in Table 1. In theformation of the surface layer, the deposited films were formed in afilm thickness of 1,000 Å for each time. The deposited films thus formedwere each subjected to fluorine treatment under conditions as shown inTable 2 while repeating etching in a depth of 500 Å, to form surfacelayers containing fluorine atoms comprising the deposited films eachhaving a film thickness as shown in Table 13. CF₄ gas was used as thefluorine source.

                  TABLE 13    ______________________________________    Deposited film              Etching depth                          Surface layer                                     Light-receiving    thickness (Å)              (Å)     thickness (Å)                                     member    ______________________________________    1,000     500         1,000      (L)    1,000     500         2,000      (M)    1,000     500         3,000      (N)    1,000     500         4,000      (O)    ______________________________________

To evaluate the water repellency of the above four light-receivingmembers (L) to (O), the contact angles of their surfaces with respect topure water were measured in the same manner as in ExperimentalExample 1. As a result, all the light-receiving members showed a contactangle of 100 degrees or greater, having achieved a high waterrepellency.

Next, these four light-receiving members were tested in the same manneras in Experimental Example 1 by continuous paper feed running on A4-size1,000,000 sheets in an environment of high temperature and high humidityof 30° C. and 80% RH to make evaluation on smeared images. In this test,like Experimental Example 1, the respective steps were repeated withoutusing any heating means for the light-receiving member.

The results obtained in the above evaluation are shown in Table 14.

In the 1,000,000 sheets running, all the light-receiving members causedno faulty images such as smeared images and stains at all. As is seenfrom the results, the effect of the present invention can be obtainedwhen a pair of the film formation and the etching treatment isrepeatedly carried out at least two times.

Evaluation was also made on wire contamination of the corona assemblyduring the running, which was evaluated on the basis of uneven halftoneimage density in the same manner as in Experimental Example 1.

The results obtained in the above evaluation are shown in Table 15. Asis seen from the results, in the 1,000,000 sheets running, all thelight-receiving members caused no uneven density in lines due to wirecontamination.

                  TABLE 14    ______________________________________    Initial  1 × 10.sup.5                     3 × 10.sup.5                              5 × 10.sup.5                                     8 × 10.sup.5                                            1 × 10.sup.6    stage    sheets  sheets   sheets sheets sheets    ______________________________________    Experimental Example 7:    (L)  A       A       A      A      A      A    (M)  A       A       A      A      A      A    (N)  A       A       A      A      A      A    (O)  A       A       A      A      A      A    ______________________________________     A: No smeared images.     B: Smeared images partly occur in some cases.     C: Smeared images occur over the whole area in some cases.

                  TABLE 15    ______________________________________    Experimental Example 7:    Initial  1 × 10.sup.5                      3 × 10.sup.5                               5 × 10.sup.5                                      8 × 10.sup.5                                             1 × 10.sup.6    stage    sheets   sheets   sheets sheets sheets    ______________________________________    (L)  AA      AA       AA     AA     AA     AA    (M)  AA      AA       AA     AA     AA     AA    (N)  AA      AA       AA     AA     AA     AA    (O)  AA      AA       AA     AA     AA     AA    ______________________________________     Uneven halftone image density:     AA: Very well free of uneven density.     A: Well free of uneven density.     B: Uneven density partly occur (no problem in practical use).     C: Uneven density in lines occur over the whole area of images in some     cases.

EXPERIMENTAL EXAMPLE 8

A light-receiving member was produced using the plasma-assisted CVDapparatus shown in FIG. 2, under conditions as shown in Table 16. In theformation of the surface layer, the deposited films were formed in alayer thickness of 1,000 Å for each time. The deposited films thusformed were each subjected to fluorine treatment under conditions asshown in Table 2 while repeating etching in a depth of 500 Å, to form asurface layer containing fluorine atoms and having a layer thickness of3,000 Å in total.

To evaluate the water repellency of the above light-receiving member,the contact angle of its surface with respect to pure water was measuredin the same manner as in Experimental Example 1. As a result, thelight-receiving member showed a contact angle of 100 degrees or greater,having achieved a high water repellency.

Next, this light-receiving member was tested in the same manner as inExperimental Example 1 by continuous paper feed running on A4-size1,000,000 sheets in an environment of high temperature and high humidityof 30° C. and 80% RH to make evaluation on smeared images. In this test,like Experimental Example 1, the respective steps were repeated withoutusing any heating means for the light-receiving member.

The results obtained in the above evaluation are shown in Table 17. Asis seen from the results, in the 1,000,000 sheets running, thelight-receiving member caused no faulty images such as smeared imagesand stains at all.

Evaluation was also made on wire contamination of the corona assemblyduring the running, which was evaluated on the basis of uneven halftoneimage density in the same manner as in Experimental Example 1.

The results obtained in the above evaluation are shown in Table 18. Asis seen from the results, in the 1,000,000 sheets running, thelight-receiving member caused no uneven density in lines due to wirecontamination.

It has been found from the foregoing results that the surface layer wasnot affected by layer configuration of other layers and by dischargefrequency.

                  TABLE 16    ______________________________________    Conditions for Production of Light-receiving Member    ______________________________________    Lower blocking layer    SiH.sub.4           300 SCCM    H.sub.2             500 SCCM    B.sub.2 H.sub.6     2,000 ppm    Power               100 W (13.56 MHz)    Internal pressure   0.2 mTorr    Layer thickness     1 μm    Charge transport layer    SiH.sub.4           500 SCCM    H.sub.2             500 SCCM    CH.sub.4            50 SCCM    Power               300 W (13.56 MHz)    Internal pressure   0.2 mTorr    Layer thickness     15 μm    Charge generation layer    SiH.sub.4           500 SCCM    H.sub.2             500 SCCM    Power               300 W (13.56 MHz)    Internal pressure   0.2 mTorr    Layer thickness     5 μm    Surface layer    SiH.sub.4           50 SCCM    CH.sub.4            500 SCCM    Power               100 W (105 MHz)    Internal pressure   20 mTorr    Layer thickness     0.3 μm    ______________________________________

                  TABLE 17    ______________________________________    Experimental Example 8:    Initial           1 × 10.sup.5                     3 × 10.sup.5                             5 × 10.sup.5                                     8 × 10.sup.5                                           1 × 10.sup.6    stage  sheets    sheets  sheets  sheets                                           sheets    ______________________________________    A      A         A       A       A     A    ______________________________________     A: No smeared images.     B: Smeared images partly occur in some cases.     C: Smeared images occur over the whole area in some cases.

                  TABLE 18    ______________________________________    Experimental Example 8:    Initial           1 × 10.sup.5                     3 × 10.sup.5                             5 × 10.sup.5                                     8 × 10.sup.5                                           1 × 10.sup.6    stage  sheets    sheets  sheets  sheets                                           sheets    ______________________________________    AA     AA        AA      AA      AA    AA    ______________________________________     Uneven halftone image density:     AA: Very well free of uneven density.     A: Well free of uneven density.     B: Uneven density partly occur (no problem in practical use).     C: Uneven density in lines occur over the whole area of images in some     cases.

EXPERIMENTAL EXAMPLE 9

Light-receiving member were produced using the plasma-assisted CVDapparatus described with reference to FIGS. 5 to 7, under conditions asshown in Table 1. In the formation of the surface layer, formation ofthe deposited film having in a film thickness of 1,000 Å for one timeand the fluorine treatment of the deposited film thus formed underconditions as shown in Table 2 for etching in a depth of 500 Å wererepeated to form a surface layer containing fluorine atoms and having alayer thickness of 3,000 Å in total.

To evaluate the water repellency of the above light-receiving members,the contact angles of their surfaces with respect to pure water weremeasured in the same manner as in Experimental Example 1. As a result,the light-receiving member showed a contact angle of 100 degrees orgreater, having achieved a high water repellency.

Next, this light-receiving member was tested in the same manner as inExperimental Example 1 by continuous paper feed running on A4-size1,000,000 sheets in an environment of high temperature and high humidityof 30° C. and 80% RH to make evaluation on smeared images. In this casealso, like Experimental Example 1, the running was tested without usingany heating means for the light-receiving member.

The results obtained in the above evaluation are shown in Table 19. Asis seen from the results, in the 1,000,000 sheets running, thelight-receiving member caused no faulty images such as smeared imagesand stains at all.

Evaluation was also made on wire contamination of the corona assemblyduring the running, which was evaluated on the basis of uneven halftoneimage density in the same manner as in Experimental Example 1.

The results obtained in the above evaluation are shown in Table 20. Asis seen from the results, in the 1,000,000 sheets running, thelight-receiving member caused no uneven density in lines due to wirecontamination.

It has been found from the foregoing results that the production processof the present invention brought about good results without regard tothe constitution of the film forming apparatus.

                  TABLE 19    ______________________________________    Experimental Example 9:    Initial           1 × 10.sup.5                     3 × 10.sup.5                             5 × 10.sup.5                                     8 × 10.sup.5                                           1 × 10.sup.6    stage  sheets    sheets  sheets  sheets                                           sheets    ______________________________________    A      A         A       A       A     A    ______________________________________     A: No smeared images.     B: Smeared images partly occur in some cases.     C: Smeared images occur over the whole area in some cases.

                  TABLE 20    ______________________________________    Experimental Example 9:    Initial           1 × 10.sup.5                     3 × 10.sup.5                             5 × 10.sup.5                                     8 × 10.sup.5                                           1 × 10.sup.6    stage  sheets    sheets  sheets  sheets                                           sheets    ______________________________________    AA     AA        AA      AA      AA    AA    ______________________________________     Uneven halftone image density:     AA: Very well free of uneven density.     A: Well free of uneven density.     B: Uneven density partly occur (no problem in practical use).     C: Uneven density in lines occur over the whole area of images in some     cases.

EXPERIMENTAL EXAMPLE 10

Light-receiving members were produced using the plasma-assisted CVDapparatus shown in FIG. 2. The lower blocking layer, photoconductivelayer and surface layer were formed under conditions as shown in Table21. Here, the deposited film constituting the surface layer was formedin a film thickness of 1,000 Å. The deposited film of 1,000 Å thick thusformed was subjected to etching under conditions as shown in Table 22 toetch the film in a depth of 500 Å. Thereafter, the film formation andthe etching treatment were repeated under the same conditions to form asurface layer containing fluorine atoms and having a layer thickness of3,000 Å in total. As fluorine sources, CF₄, CHF₃ and ClF₃ wererespectively used so that corresponding three light-receiving memberswere produced.

To evaluate the water repellency of the above light-receiving members,the contact angles of their surfaces with respect to pure water weremeasured using the contact angle meter. As a result, they all showed acontact angle of 100 degrees or greater, having achieved a high waterrepellency.

Then, these light-receiving members were each mounted on the copyingmachine previously described, and continuous paper feed running on1,000,000 sheets of A4-size paper was tested in an environment of hightemperature and high humidity of 30° C. and 80% RH to make evaluation onsmeared images. In this test, the steps of charging, exposure,development, transfer, separation and scrape cleaning were repeated inorder, without using any heating means for the light-receiving member.

(Evaluation on Smeared Images)

As an evaluation method on smeared images, the evaluation was made usinga test chart with 6 point or smaller characters printed on the wholesurface. Taking account of the effect of paper dust on images in thecase when reclaimed paper, recently used increasingly, or low-qualitypaper is used, the reclaimed paper was used this time. The paper usedthis time contains fillers such as talc in a large quantity, which areknown to greatly affect the characteristics on smeared images.

The results obtained in the above evaluation are shown in Table 23. InTable 23 and the subsequent similar tables, letter symbols denote asfollows:

A: Clear images.

B: Smeared images partly occur in some cases.

C: Smeared images occur over the whole area in some cases.

As is seen from the results, in the 1,000,000 sheets running, all thelight-receiving members caused no faulty images such as smeared imagesand stains at all. After the 1,000,000 sheets running, the contact anglewas again measured. As the result, it was 100 degrees or greater in allthe light-receiving members, finding that it was possible to maintainthe initial water repellency.

Evaluation was also made on wire contamination of the corona assemblyafter the running, which was evaluated on the basis of uneven halftoneimage density.

(Halftone Evaluation)

A method for the evaluation on uneven halftone image density will bedescribed below with reference to FIG. 4.

The amount of charge electric current of the primary corona assembly 402was so controlled that the dark portion potential at the position of thedeveloping assembly 404 was 400 V. An original 412 with a reflectiondensity of 0.3 was placed on the original glass plate 411, and thelighting voltage of the halogen lamp 410 was so controlled that thelight portion potential was 200 V, where A3-size halftone images wereformed. Using the images thus formed, any uneven density in lines causedby the wire contamination was observed.

The results obtained in the above evaluation are shown together in Table23. In Table 23 and the subsequent similar tables, letter symbols denoteas follows:

AA: Very well free of uneven density.

A: Well free of uneven density.

B: Uneven density partly occur (no problem in practical use).

C: Uneven density in lines occur over the whole area of images in somecases.

As is seen from the results, even in the 1,000,000 sheets running, allthe light-receiving members caused no uneven density in lines due towire contamination. It has been found from this result that, as for gasspecies used in the etching, it was possible to maintain the initialcleaning performance when any fluorine type gases are used.

                  TABLE 21    ______________________________________    Conditions for Production of Light-receiving Member    ______________________________________    Lower blocking layer    SiH.sub.4       300 SCCM    H.sub.2         500 SCCM    NO              8 SCCM    B.sub.2 H.sub.6 2,000 ppm    Power           100 W (13.56 MHz)    Internal pressure                    0.4 Torr    Layer thickness 1 μm    Photoconductive layer    SiH.sub.4       500 SCCM    H.sub.2         500 SCCM    Power           400 W (13.56 MHz)    Internal pressure                    0.5 Torr    Layer thickness 20 μm    Surface layer    CH.sub.4        500 SCCM    Power           1,000 W (105 MHz)    Internal pressure                    10 mTorr    Layer thickness 0.3 μm    ______________________________________

                  TABLE 22    ______________________________________    Conditions for Fluorine Treatment    ______________________________________    CF.sub.4            400 SCCM    Substrate temperature                        250° C.    Pressure            20 mTorr    Power               500 W (105 MHz)    Etching depth       0.05 μm    ______________________________________

                  TABLE 23    ______________________________________    Running test    (× 10,000 sheets)                      Halftone uneven density    Initial  10    50    80  100  Initial                                       10   50   80   100    ______________________________________    Experimental Example 1:    CF.sub.4          A      A     A   A   A    AA   AA   AA   AA   AA    CHF.sub.3          A      A     A   A   A    AA   AA   AA   AA   AA    ClF.sub.3          A      A     A   A   A    AA   AA   AA   AA   AA    ______________________________________

EXPERIMENTAL EXAMPLE 11

Light-receiving members were produced in the same manner as inExperimental Example 10 while repeating the film formation and theetching treatment to form the surface layer in a layer thickness of3,000 Å in total, except that, in the formation of the surface layer,the deposited films were formed, and etched by fluorine treatment, inthe film thickness and the depth, respectively, in five ways as shown inTable 24 below. CF₄ gas was used as the fluorine source.

                  TABLE 24    ______________________________________    Deposited film    thickness     Etching depth                             Light-receiving    (Å)       (Å)    member    ______________________________________    520           20         (L)    550           50         (M)    600           100        (N)    1,000         500        (O)    1,500         1,000      (P)    ______________________________________

To evaluate the water repellency of the above five light-receivingmembers (L) to (P), the contact angles of their surfaces with respect topure water were measured in the same manner as in Experimental Example10. As a result, all the light-receiving members showed a contact angleof 100 degrees or greater, having achieved a high water repellency.

Next, these five light-receiving members were running tested in the samemanner as in Experimental Example 10 while similarly repeating the stepsof charging, exposure, development, transfer, separation and scrapecleaning were repeated in order.

The results obtained in the above evaluation are shown in Table 25.

As is seen from the results, in the 1,000,000 sheets running, all thelight-receiving members caused no faulty images such as smeared imagesand stains at all. After the 1,000,000 sheets running, the contact anglewas again measured. As the result, it was 100 degrees or greater in allthe light-receiving members, finding that it was possible to maintainthe initial water repellency so long as the etching for each time was ina depth of at least 20 Å.

Evaluation was also made on wire contamination of the corona assemblyduring the running, which was evaluated on the basis of uneven halftoneimage density in the same manner as in Experimental Example 10. Theresults obtained in this evaluation are shown in Table 25.

In the 1,000,000 sheets running, all the light-receiving members causedno uneven density in lines due to the wire contamination. It has beenfound from this result that it was possible to maintain the initialwater repellency so long as the etching for each time was in a depth ofat least 20 Å.

                  TABLE 25    ______________________________________    Running test    (× 10,000 sheets)                      Halftone uneven density    Initial  10    50    80  100  Initial                                       10   50   80   100    ______________________________________    Experimental Example 11:    (L)   A      A     A   A   A    AA   AA   AA   AA   AA    (M)   A      A     A   A   A    AA   AA   AA   AA   AA    (N)   A      A     A   A   A    AA   AA   AA   AA   AA    (O)   A      A     A   A   A    AA   AA   AA   AA   AA    (P)   A      A     A   A   A    AA   AA   AA   AA   AA    ______________________________________

EXPERIMENTAL EXAMPLE 12

Light-receiving members were produced in the same manner as inExperimental Example 10 while repeating the film formation and theetching treatment plural times to form the surface layer in a layerthickness of 4,000 Å in total, except that, in the formation of thesurface layer, the deposited films were formed, and etched by fluorinetreatment, in the film thickness and the depth, respectively, in sixways as shown in Table 26 below. CF₄ gas was used as the fluorinesource.

                  TABLE 26    ______________________________________    Deposited film    thickness     Etching depth                             Light-receiving    (Å)       (Å)    member    ______________________________________    520           500        (Q)    550           500        (R)    600           500        (S)    1,000         500        (T)    1,500         500        (U)    2,500         500        (V)    ______________________________________

To evaluate the water repellency of the above six light-receivingmembers (Q) to (V), the contact angles of their surfaces with respect topure water were measured in the same manner as in Experimental Example10. As a result, all the light-receiving members showed a contact angleof 100 degrees or greater, having achieved a high water repellency.

Next, these six light-receiving members were running tested in the samemanner as in Experimental Example 10 while similarly repeating the stepsof charging, exposure, development, transfer, separation and scrapecleaning were repeated in order.

The results obtained in the above evaluation are shown in Table 27.

As is seen from the results, in the 1,000,000 sheets running, all thelight-receiving members caused no smeared images at all. After the1,000,000 sheets running, the contact angle was again measured. As theresult, it was 100 degrees or greater in the light-receiving membersother than (K), finding that it was possible to maintain the initialwater repellency. With regard to the light-receiving member (K),however, the contact angle was 50 degrees after 1,000,000 sheetsrunning. All the light-receiving members caused no faulty images such asstains.

Evaluation was also made on wire contamination of the corona assemblyduring the running, which was evaluated on the basis of uneven halftoneimage density in the same manner as in Experimental Example 10. Theresults obtained in this evaluation are shown in Table 27.

As is seen from the results, in the 1,000,000 sheets running, all thelight-receiving members caused no uneven density in lines due to thewire contamination.

It has been found from the foregoing results that the surface layerformed by repeating film formation and etching may preferably have alayer thickness not larger than 2,000 Å for each layer of the depositedfilms. It has been also found that if the thickness is smaller than 20 Ådifficulties may occur such that the film uniformity is damaged or ittakes a long time for the film formation.

                  TABLE 27    ______________________________________    Running test    (× 10,000 sheets)                      Halftone uneven density    Initial  10    50    80  100  Initial                                       10   50   80   100    ______________________________________    Experimental Example 12:    (Q)   A      A     A   A   A    AA   AA   AA   AA   AA    (R)   A      A     A   A   A    AA   AA   AA   AA   AA    (S)   A      A     A   A   A    AA   AA   AA   AA   AA    (T)   A      A     A   A   A    AA   AA   AA   AA   AA    (U)   A      A     A   A   A    AA   AA   AA   AA   AA    (V)   A      A     B   B   B    AA   AA   AA   A    A    ______________________________________

EXPERIMENTAL EXAMPLE 13

Light-receiving members were produced in the same manner as inExperimental Example 10 while repeating the film formation and theetching treatment to form the surface layer in a layer thickness of4,000 Å in total, except that the surface layer was formed using ahigh-frequency power of 13.56 MHz under conditions as shown in Table 28below and the deposited films of the surface layer were formed, andetched by fluorine treatment, in the film thickness and the depth,respectively, in six ways as shown in Table 29 below. CF₄ gas was usedas the fluorine source.

                  TABLE 28    ______________________________________    Surface layer    CH.sub.4           500 SCCM    Power              1,000 W (13.56 MHz)    Internal pressure  0.4 Torr    Etching conditions    CF.sub.4           200 SCCM    Power              500 W (13.56 MHz)    Internal pressure  0.4 Torr    ______________________________________

                  TABLE 29    ______________________________________    Deposited film    thickness     Etching depth                             Light-receiving    (Å)       (Å)    member    ______________________________________    520           500        (Q')    550           500        (R')    600           500        (S')    1,000         500        (T')    1,500         500        (U')    2,500         500        (V')    ______________________________________

To evaluate the water repellency of the above six light-receivingmembers (Q') to (V'), the contact angles of their surfaces with respectto pure water were measured in the same manner as in ExperimentalExample 10. As a result, all the light-receiving members showed acontact angle of 100 degrees or greater, having achieved a high waterrepellency.

Next, these six light-receiving members were running tested in the samemanner as in Experimental Example 10 while similarly repeating the stepsof charging, exposure, development, transfer, separation and scrapecleaning were repeated in order.

The results obtained in the above evaluation are shown in Table 30.

As is seen from the results, in the 1,000,000 sheets running, all thelight-receiving members caused no smeared images at all. After the1,000,000 sheets running, the contact angle was again measured. As theresult, it was 100 degrees or greater in the light-receiving membersother than (K'), finding that it was possible to maintain the initialwater repellency. With regard to the light-receiving member (K),however, the contact angle was 50 degrees after 1,000,000 sheetsrunning. All the light-receiving members caused no faulty images such asstains.

Evaluation was also made on wire contamination of the corona assemblyduring the running, which was evaluated on the basis of uneven halftoneimage density in the same manner as in Experimental Example 10. Theresults obtained in this evaluation are shown in Table 30.

As is seen from the results, in the 1,000,000 sheets running, all thelight-receiving members caused uneven density in lines due to the wirecontamination, but on the level of no problem in practical use.

                  TABLE 30    ______________________________________    Running test    (× 10,000 sheets)                       Halftone uneven density    Initial 10     50    80   100  Initial                                        10   50  80   100    ______________________________________    Experimental Example 13:    (Q') A      A      A   A    A    A    A    A   A    A    (R') A      A      A   A    A    A    A    A   A    A    (S') A      A      A   A    A    A    A    A   A    A    (T') A      A      A   A    A    A    A    A   A    A    (U') A      A      A   A    A    A    A    A   A    A    (V') A      A      B   B    B    A    A    A   B    B    ______________________________________

EXPERIMENTAL EXAMPLE 14

Using the plasma-assisted CVD apparatus shown in FIG. 2, light-receivingmembers were produced in the same manner as in Experimental Example 10,forming the surface layer containing fluorine atoms while carrying outthe film formation and the etching treatment under conditions in sixways as shown in Table 31 below, using CF₄ gas as the fluorine source.

                  TABLE 31    ______________________________________    Deposited film               Etching    Surface layer                                    Light-    thickness  depth      thickness receiving    (Å)    (Å)    (Å)   member    ______________________________________    1,000      500        1,000     (X1)    1,000      500        2,000     (X2)    1,000      500        3,000     (X3)    1,000      500        4,000     (X4)    ______________________________________

To evaluate the water repellency of the above five light-receivingmembers (X1) to (X4), the contact angles of their surfaces with respectto pure water were measured in the same manner as in ExperimentalExample 10. As a result, all the light-receiving members showed acontact angle of 100 degrees or greater, having achieved a high waterrepellency.

Next, these four light-receiving members were running tested in the samemanner as in Experimental Example 10 while similarly repeating the stepsof charging, exposure, development, transfer, separation and scrapecleaning were repeated in order.

The results obtained in the above evaluation are shown in Table 32.

In the 1,000,000 sheets running, all the light-receiving members causedno faulty images such as smeared images and stains at all. As is seenfrom the results, the effect of the present invention can be obtainedwhen the operation of the film formation and the etching treatment arecarried out repeatedly at least twice.

Evaluation was also made on wire contamination of the corona assemblyduring the running, which was evaluated on the basis of uneven halftoneimage density in the same manner as in Experimental Example 10. Theresults obtained in this evaluation are shown in Table 32. As is seenfrom the results, in the 1,000,000 sheets running, all thelight-receiving members caused no uneven density in lines due to wirecontamination.

                  TABLE 32    ______________________________________    Running test    (× 10,000 sheets)                      Halftone uneven density    Initial  10    50    80  100  Initial                                       10   50   80   100    ______________________________________    Experimental Example 14:    (X1)  A      A     A   A   A    AA   AA   AA   AA   AA    (X2)  A      A     A   A   A    AA   AA   AA   AA   AA    (X3)  A      A     A   A   A    AA   AA   AA   AA   AA    (X4)  A      A     A   A   A    AA   AA   AA   AA   AA    ______________________________________

EXPERIMENTAL EXAMPLE 15

A light-receiving member was produced using the plasma-assisted CVDapparatus shown in FIG. 2, under conditions as shown in Table 33. In theformation of the surface layer, the deposited films were formed in afilm thickness of 1,000 Å for each time. The deposited films thus formedwere each subjected to fluorine treatment under conditions as shown inTable 22 to carry out etching in a depth of 500 Å, to thereby form asurface layer containing fluorine atoms, and having a layer thickness of3,000 Å in total.

To evaluate the water repellency of the above light-receiving member,the contact angle of its surface with respect to pure water was measuredin the same manner as in Experimental Example 10. As a result, thelight-receiving member showed a contact angle of 100 degrees or greater,having achieved a high water repellency.

Next, this light-receiving member was running tested in the same manneras in Experimental Example 10.

The results obtained in the above evaluation are shown in Table 34. Asis seen from the results, in the 1,000,000 sheets running, thelight-receiving member caused no faulty images such as smeared imagesand stains at all.

Evaluation was also made on wire contamination of the corona assemblyduring the running, which was evaluated on the basis of uneven halftoneimage density in the same manner as in Experimental Example 10. Theresults obtained in this evaluation are shown in Table 34. As is seenfrom the results, in the 1,000,000 sheets running, the light-receivingmember caused no uneven density in lines due to the wire contamination.

It has been found from the foregoing results that the present inventioncan be effective under any layer configuration and discharge frequenciesexcept for those in the surface layer.

                  TABLE 33    ______________________________________    Conditions for Production of Light-receiving Member    ______________________________________    Lower blocking layer    SiH.sub.4           300 SCCM    H.sub.2             500 SCCM    B.sub.2 H.sub.6     2,000 ppm    Power               100 W (13.56 MHz)    Internal pressure   0.4 Torr    Layer thickness     1 μm    Charge transport layer    SiH.sub.4           500 SCCM    H.sub.2             500 SCCM    CH.sub.4            50 SCCM    Power               300 W (13.56 MHz)    Internal pressure   0.6 Torr    Layer thickness     15 μm    Charge generation layer    SiH.sub.4           500 SCCM    H.sub.2             500 SCCM    Power               300 W (13.56 MHz)    Internal pressure   0.5 Torr    Layer thickness     5 μm    Surface layer    CH.sub.4            500 SCCM    Power               1,000 W (105 MHz)    Internal pressure   15 mTorr    Layer thickness     0.3 μm    ______________________________________

                  TABLE 34    ______________________________________    Running test    (× 10,000 sheets)                    Halftone uneven density    Initial         10     50    80   100  Initial                                     10    50   80    100    ______________________________________    Experimental Example 15:    A    A      A     A    A    AA   AA    AA   AA    AA    ______________________________________

EXPERIMENTAL EXAMPLE 16

A light-receiving member was produced using the plasma-assisted CVDapparatus shown in FIGS. 5 to 7, under conditions as shown in Table 21.In the formation of the surface layer, the deposited films were formedin a film thickness of 1,000 Å for each time. The deposited films thusformed were each subjected to fluorine treatment under conditions asshown in Table 22 to carry out etching in a depth of 500 Å, to therebyform a surface layer containing fluorine atoms and having a layerthickness of 3,000 Å in total.

To evaluate the water repellency of the above light-receiving member,the contact angle of its surface with respect to pure water was measuredin the same manner as in Experimental Example 10. As a result, thelight-receiving member showed a contact angle of 100 degrees or greater,having achieved a high water repellency.

Next, this light-receiving member was running tested in the same manneras in Experimental Example 10.

The results obtained in the above evaluation are shown in Table 35. Asis seen from the results, in the 1,000,000 sheets running, thelight-receiving member caused no faulty images such as smeared imagesand stains at all.

Evaluation was also made on wire contamination of the corona assemblyduring the running, which was evaluated on the basis of uneven halftoneimage density in the same manner as in Experimental Example 10. Theresults obtained in this evaluation are shown in Table 35. As is seenfrom the results, in the 1,000,000 sheets running, the light-receivingmember caused no uneven density in lines due to the wire contamination.

It has been found from the foregoing results that the production processof the present invention can bring about good results when thelight-receiving member is produced using apparatus having anyconstruction.

                  TABLE 35    ______________________________________    Running test    (× 10,000 sheets)                    Halftone uneven density    Initial         10     50    80   100  Initial                                     10    50   80    100    ______________________________________    Experimental Example 16:    A    A      A     A    A    AA   AA    AA   AA    AA    ______________________________________

EXPERIMENTAL EXAMPLE 17

Light-receiving members were produced using the plasma-assisted CVDapparatus shown in FIG. 2. The lower blocking layer and photoconductivelayer were formed under conditions as shown in Table 36. At the time itwas completed to form films up to the photoconductive layer, its surfacewas etched under conditions as shown in Table 37, and thereafter thefilm formation and etching to form the surface layer were carried outtwice under conditions as shown in Tables 38 and 37, respectively. Thus,the surface layer of the present invention was formed. In the formationof this surface layer, the deposited films were each formed in a filmthickness of 1,000 Å and etched in a depth of 200 Å so as to be in alayer thickness of 1,600 Å in total.

To evaluate the water repellency of the above light-receiving member,the contact angle of its surface with respect to pure water was measuredin the same manner as in Experimental Example 10. As a result, thelight-receiving member showed a contact angle of 100 degrees or greater,having achieved a high water repellency.

Next, this light-receiving member was running tested in the same manneras in Experimental Example 10.

The results obtained in the above evaluation are shown in Table 39. Asis seen from the results, in the 1,000,000 sheets running, thelight-receiving member caused no faulty images such as smeared imagesand stains at all.

Evaluation was also made on wire contamination of the corona assemblyduring the running, which was evaluated on the basis of uneven halftoneimage density in the same manner as in Experimental Example 10. Theresults obtained in this evaluation are shown in Table 39. As is seenfrom the results, in the 1,000,000 sheets running, the light-receivingmember caused no uneven density in lines due to the wire contamination.

                  TABLE 36    ______________________________________    Conditions for Production of Light-receiving Member    ______________________________________    Lower blocking layer    SiH.sub.4           100 SCCM    H.sub.2             500 SCCM    NO                  5 SCCM    B.sub.2 H.sub.6     1,500 ppm    Power               100 W (13.56 MHz)    Internal pressure   0.5 Torr    Substrate temperature                        250° C.    Layer thickness     2 μm    Photoconductive layer    SiH.sub.4           300 SCCM    H.sub.2             500 SCCM    Power               400 W (13.56 MHz)    Internal pressure   0.5 Torr    Substrate temperature                        250° C.    Layer thickness     20 μm    ______________________________________

                  TABLE 37    ______________________________________    Conditions for Fluorine Treatment    ______________________________________    CF.sub.4            300 SCCM    Substrate temperature                        250° C.    Pressure            20 mTorr    Power               500 W (105 MHz)    Etching depth       0.02 μm    ______________________________________

                  TABLE 38    ______________________________________    Conditions for Surface Layer Formation    Surface layer    ______________________________________    CH.sub.4            500 SCCM    Power               1,500 W (105 MHz)    Internal pressure   20 mTorr    Substrate temperature                        250° C.    Layer thickness     0.1 μm    ______________________________________

                  TABLE 39    ______________________________________    Running test    (× 10,000 sheets)                    Halftone uneven density    Initial         10     50    80   100  Initial                                     10    50   80    100    ______________________________________    Experimental Example 17:    A    A      A     A    A    AA   AA    AA   AA    AA    ______________________________________

EXPERIMENTAL EXAMPLE 18

Light-receiving members were produced using the plasma-assisted CVDapparatus shown in FIG. 2. The lower blocking layer, photoconductivelayer and surface layer were formed under conditions as shown in Table40. In the present Experimental Example, the process of film formationand etching to form the surface layer was carried out five times, andthe surface layer film forming conditions in each process were varied asshown in Table 40. The deposited films were etched under conditions asshown in Table 41.

To evaluate the water repellency of the above light-receiving member,the contact angle of its surface with respect to pure water was measuredin the same manner as in Experimental Example 10. As a result, thelight-receiving member showed a contact angle of 100 degrees or greater,having achieved a high water repellency.

Next, this light-receiving member was running tested in the same manneras in Experimental Example 10.

The results obtained in the above evaluation are shown in Table 42. Asis seen from the results, in the 1,000,000 sheets running, thelight-receiving member caused no faulty images such as smeared imagesand stains at all.

Evaluation was also made on wire contamination of the corona assemblyduring the running, which was evaluated on the basis of uneven halftoneimage density in the same manner as in Experimental Example 10. Theresults obtained in this evaluation are shown in Table 42. As is seenfrom the results, in the 1,000,000 sheets running, the light-receivingmember caused no uneven density in lines due to wire contamination.

                  TABLE 40    ______________________________________    Conditions for Production of Light-receiving Member    ______________________________________    Lower blocking layer    SiH.sub.4          100 SCCM    H.sub.2            500 SCCM    NO                 5 SCCM    B.sub.2 H.sub.6    500 ppm    Power              100 W (13.56 MHz)    Internal pressure  0.5 Torr    Substrate temperature                       200° C.    Layer thickness    2 μm    Photoconductive layer    SiH.sub.4          300 SCCM    H.sub.2            500 SCCM    Power              400 W (13.56 MHz)    Internal pressure  0.5 Torr    Substrate temperature                       200° C.    Layer thickness    20 μm    Surface layer    (1st layer) SiH.sub.4                       40 SCCM → 30 SCCM    (2nd layer) SiH.sub.4                       30 SCCM → 20 SCCM    (3rd layer) SiH.sub.4                       20 SCCM → 10 SCCM    (4th layer) SiH.sub.4                       10 SCCM → 0 SCCM    (5th layer) SiH.sub.4                       0 SCCM    Common conditions:    CH.sub.4           500 SCCM    Power              100 W (105 MHz)    Internal pressure  20 mTorr    Substrate temperature                       200° C.    Layer thickness    0.1 μm    ______________________________________

                  TABLE 41    ______________________________________    Conditions for Fluorine Treatment    ______________________________________    CF.sub.4            400 SCCM    Substrate temperature                        200° C.    Pressure            20 mTorr    Power               600 W (105 MHz)    Etching depth       0.05 μm    ______________________________________

                  TABLE 42    ______________________________________    Running test    (× 10,000 sheets)                    Halftone uneven density    Initial         10     50    80   100  Initial                                     10    50   80    100    ______________________________________    Experimental Example 18:    A    A      A     A    A    AA   AA    AA   AA    AA    ______________________________________

EXPERIMENTAL EXAMPLE 19

A lower blocking layer (a charge injection blocking layer) and aphotoconductive layer were formed as the receiving layer underconditions as shown in Table 1, and thereafter the surface of thephotoconductive layer was subjected to fluorine treatment underconditions as shown in Table 22. Subsequently, a surface layer wasformed thereon in a thickness of 0.3 μm under conditions as shown inTable 21, and thereafter its surface was further subjected to fluorinetreatment under conditions as shown in Table 22. As a result, likeExperimental Example 10, a light-receiving member having superiorperformances were obtained.

EXPERIMENTAL EXAMPLE 20

A lower blocking layer and a photoconductive layer were formed as thereceiving layer under conditions as shown in Table 1. Thereafter, a 0.3μm thick a-SiC layer was formed thereon under the surface layer formingconditions as shown in Table 1, and the surface of the a-SiC layer wassubjected to fluorine treatment under conditions as shown in Table 2.Subsequently, a layer was formed on the fluorine-treated a-SiC layer ina thickness of 1,000 A under the surface layer forming conditions asshown in Table 21, and thereafter its surface was further subjected tofluorine treatment under conditions as shown in Table 22. Thelight-receiving member thus obtained was, like Experimental Example 10,a light-receiving member having superior performances.

EXPERIMENTAL EXAMPLE 21

A lower blocking layer and a photoconductive layer were formed underconditions as shown in Table 43. Thereafter, a deposited film was formedthereon under the surface layer forming conditions as shown in Table 43,and the deposited film thus formed was subjected to fluorine treatmentunder conditions as shown in Table 44 to carry out etching in a depth of500 Å. Subsequently, the operation to form another deposited filmconstituting the surface layer, being formed in a thickness of 1,000 Åfor each deposition, and to again make the fluorine treatment underconditions as shown in Table 44 to carry out etching in a depth of 500Å, was repeated. This film formation and etching for the surface layerwere repeated plural times so as to provide a layer thickness of 3,000 Åin total to form a surface layer containing fluorine atoms.

The light-receiving member thus obtained was running tested in the samemanner as in Experimental Example 1.

As the result, in the 1,000,000 sheets running, the light-receivingmember caused no faulty images such as smeared images and stains at all.

It has been found from the foregoing results that the present inventioncan be effective also when the light-receiving member has a layerconfiguration where a-C (amorphous carbon) is used in the surface layer.

                  TABLE 43    ______________________________________    Conditions for Production of Light-receiving Member    ______________________________________    Lower blocking layer    SiH.sub.4             300 SCCM    H.sub.2               500 SCCM    NO                    8 SCCM    B.sub.2 H.sub.6       2,000 ppm    Power                 100 W    Internal pressure     0.4 Torr    Layer thickness       1 μm    Photoconductive layer    SiH.sub.4             500 SCCM    H.sub.2               500 SCCM    Power                 400 W    Internal pressure     0.5 Torr    Layer thickness       20 um    Surface layer    CH.sub.4              600 SCCM    Power                 1,000 W    Internal pressure     0.4 Torr    Layer thickness       0.1 μm    ______________________________________

                  TABLE 44    ______________________________________    Conditions for Fluorine Treatment    ______________________________________    CF.sub.4              500 SCCM    Substrate temperature 250° C.    Pressure              0.6 Torr    Power                 500 W    Etching depth         0.05 μm    ______________________________________

EXPERIMENTAL EXAMPLE 22

A lower blocking layer and a photoconductive layer were formed underconditions as shown in Table 43. Thereafter, a surface layer was formedunder conditions as shown in Table 45A. In this surface layer formation,the deposited films were formed in a film thickness of 1,000 Å for eachtime. Each deposited film thus formed was subjected to fluorinetreatment under conditions as shown in Table 44 to carry out etching ina depth of 500 Å. Subsequently, the operation to form another depositedfilm in a thickness of 1,000 Å and to again make the fluorine treatmentunder conditions as shown in Table 44 to carry out etching in a depth of500 Å, was repeated. This film formation and etching for the surfacelayer were repeated plural times so as to provide a layer thickness of3,000 Å in total to form a surface layer containing fluorine atoms.

As fluorine sources, CF₄, CHF₃ and ClF₃ were respectively used so thatcorresponding three light-receiving members were produced.

All the light-receiving members had a high contact angle of 100 degreesor greater. These were running tested in the same manner as inExperimental Example 1. As the result, in the 1,000,000 sheets running,all the light-receiving members caused no faulty images such as smearedimages and stains at all even in the case of N-containing surfacelayers. After the 1,000,000 sheets running, the contact angle was againmeasured. As the result, it was 75 degrees or greater in all thelight-receiving members.

                  TABLE 45A    ______________________________________    Conditions for Surface Layer Formation    Surface layer    ______________________________________    SiH.sub.4            50 SCCM    N.sub.2              900 SCCM    Power                100 W    Internal pressure    0.4 Torr    Layer thickness      0.3 μm    ______________________________________

EXPERIMENTAL EXAMPLE 23

A lower blocking layer, a photoconductive layer and a surface layer wereformed in order, under conditions as shown in Table 43. Here, thedeposited film constituting the surface layer was formed at one time ina layer thickness of 3,500 Å. The surface layer, thus formed, wassubjected to etching by fluorine treatment on only the outermost surfaceunder conditions as shown in Table 44, to carry out etching in a depthof 500 Å to form the surface layer in a layer thickness of 3,000 Å.

As fluorine sources, CF₄, CHF₃ and ClF₃ were respectively used so thatthree light-receiving members were produced.

To evaluate the water repellency of the above three light-receivingmembers, the contact angles of their surfaces with respect to pure waterwere measured. As a result, all the light-receiving members showed acontact angle of 100 degrees or greater, having achieved a high waterrepellency.

These light-receiving members were running tested in the same manner asin Experimental Example 1. As the result, in the 1,000,000 sheetsrunning, all the light-receiving members caused smeared images on the500,000th sheet and thereafter in some cases.

After the 1,000,000 sheets running, the contact angle of eachlight-receiving member was again measured. As the result, it was at thevalue of 50 degrees or less in all the light-receiving members.

EXPERIMENTAL EXAMPLE 24

Light-receiving members were produced in the same manner as inExperimental Example 22 while repeating the film formation and etchingto form the surface layer in a layer thickness of 3,000 Å in total,except that, in the formation of the surface layer, the deposited filmswere formed, and etched by fluorine treatment, in the layer thicknessand the depth, respectively, in five ways as shown in Table 45B below.CF₄ gas was used as the fluorine source.

                  TABLE 45B    ______________________________________    Thickness of film                     Depth of film    formed by each deposition                     etched for each time    (Å)          (Å)    ______________________________________    520              20    550              50    600              100    1,000            500    1,500            1,000    ______________________________________

The contact angles of the surfaces of the light-receiving members thusformed were measured. As a result, all the light-receiving membersshowed a contact angle of 100 degrees or greater, having achieved a highwater repellency.

These light-receiving members were also running tested in the samemanner as in Experimental Example 1. As the result, in the 1,000,000sheets running, all the light-receiving members caused no faulty imagessuch as smeared images and stains at all. After the 1,000,000 sheetsrunning, the contact angle was again measured. As the result, it was 100degrees or greater in all the light-receiving members, finding that itwas possible to maintain the initial water repellency so long as theetching for each time was in a depth of at least 20 Å.

EXPERIMENTAL EXAMPLE 25

Light-receiving members were produced in the same manner as inExperimental Example 22 while repeating the film formation and etchingto form the surface layer in a layer thickness of 4,000 Å in total,except that, in the formation of the surface layer, the deposited filmswere formed, and etched by fluorine treatment, in the layer thicknessand the depth, respectively, in six ways as shown in Table 46 below. CF₄gas was used as the fluorine source.

                  TABLE 46    ______________________________________    Thickness of film                     Depth of film    formed by each deposition                     etched for each time    (Å)          (Å)    ______________________________________    520              500    550              500    600              500    1,000            500    1,500            500    2,500            500    ______________________________________

The contact angles of the surfaces of the light-receiving members thusformed were measured. As a result, all the light-receiving membersshowed a contact angle of 100 degrees or greater, having achieved a highwater repellency.

These light-receiving members were running tested in the same manner asin Experimental Example 1. As the result, in the 1,000,000 sheetsrunning, the light-receiving members other than the one in which thedeposited film was in a layer thickness of 2,500 Å for each time causedno smeared images at all. After the 1,000,000 sheets running, thecontact angle was again measured. As the result, it was 100 degrees orgreater in the light-receiving members other than the above 2,500Å-deposited one, finding that except for the latter it was possible tomaintain the initial water repellency. With regard to the latterlight-receiving member, it partly caused smeared images in some cases onthe 500,000th sheet and thereafter, and had a contact angle of 50degrees after the 1,000,000 sheets running. All the light-receivingmembers cause no faulty images such as stains.

It has been found from the foregoing results that the surface layerformed by repeating film formation and etching may preferably have alayer thickness of 2,000 Å or less for each layer of the depositedfilms.

EXPERIMENTAL EXAMPLE 26

A lower blocking layer, a photoconductive layer and a surface layer wereformed in order, in the same manner as in Experimental Example 22,except that in the formation of the surface layer the deposited filmsconstituting the surface layer were formed in a film thickness of 1,000Å for each time. Each deposited film thus formed was subjected tofluorine treatment under conditions as shown in Table 44 to carry outetching in a depth of 500 Å. Subsequently, the operation to form anotherdeposited film in a thickness of 1,000 Å and to again make the fluorinetreatment under conditions as shown in Table 44 to carry out etching ina depth of 500 Å, was repeated. This film formation and etching for thesurface layer were repeated plural times so as to provide a layerthickness of 1,000 Å, 2,000 Å, 3,000 Å or 4,000 Å in total to form asurface layer containing fluorine atoms.

The contact angles of the surfaces of the light-receiving members thusformed were measured. As a result, all the light-receiving membersshowed a contact angle of 100 degrees or greater, having achieved a highwater repellency.

These light-receiving members were running tested in the same manner asin Experimental Example 1. As the result, in the 1,000,000 sheetsrunning, all the light-receiving members caused no faulty images such assmeared images and stains at all.

EXPERIMENTAL EXAMPLE 27

A lower blocking layer, a photoconductive layer and a surface layer wereformed in order, under conditions as shown in Table 47. Here, in theformation of the surface layer, the deposited films constituting thesurface layer of a light-receiving member were formed in a filmthickness of 1,000 Å for each time. The deposited film thus formed wassubjected to fluorine treatment under conditions as shown in Table 44 tocarry out etching in a depth of 500 Å. Subsequently, the operation toform another deposited film in a thickness of 1,000 Å and to again makethe fluorine treatment under conditions as shown in Table 44 to carryout etching in a depth of 500 Å, was repeated. This film formation andetching for the surface layer were repeated plural times so as toprovide a layer thickness of 3,000 Å in total to form a surface layercontaining fluorine atoms.

The contact angle of the surface of the light-receiving member thusformed was measured. As a result, it showed a contact angle of 100degrees or greater, having achieved a high water repellency.

Next, this light-receiving member was running tested in the same manneras in Experimental Example 1 to find that it similarly had superiorperformances.

                  TABLE 47    ______________________________________    Conditions for Production of Light-receiving Member    ______________________________________    Lower blocking layer    SiH.sub.4             300 SCCM    H.sub.2               500 SCCM    B.sub.2 H.sub.6       2,000 ppm    Power                 100 W    Internal pressure     0.4 Torr    Layer thickness       1 μm    Charge transport layer    SiH.sub.4             500 SCCM    H.sub.2               500 SCCM    CH.sub.4              50 SCCM    Power                 300 W    Internal pressure     0.5 Torr    Layer thickness       15 μm    Charge generation layer    SiH.sub.4             500 SCCM    H.sub.2               500 SCCM    Power                 300 W    Internal pressure     0.5 Torr    Layer thickness       5 μm    Surface layer    SiH.sub.4             50 SCCM    N.sub.2               900 SCCM    Power                 100 W    Internal pressure     0.4 Torr    Layer thickness       0.3 μm    ______________________________________

EXPERIMENTAL EXAMPLE 28

A lower blocking layer and a photoconductive layer were formed in thesame manner as in Experimental Example 21. Thereafter, a surface layerwas formed under conditions as shown in Table 48. In this surface layerformation, the deposited films constituting the surface layer wereformed in a film thickness of 1,000 Å for each time. The deposited filmthus formed was subjected to fluorine treatment under conditions asshown in Table 44 to carry out etching in a depth of 500 Å.Subsequently, the operation to form another deposited film in athickness of 1,000 Å and to again make the fluorine treatment underconditions as shown in Table 44 to carry out etching in a depth of 500Å, was repeated. This film formation and etching for the surface layerwere repeated plural times so as to provide a layer thickness of 3,000 Åin total to form a surface layer containing fluorine atoms.

The contact angle of the surface of the light-receiving member thusformed was measured. As a result, it showed a contact angle of 100degrees or greater, having achieved a high water repellency.

This light-receiving member was running tested in the same manner as inExperimental Example 1 to find that it similarly had superiorperformances.

It has been found from the foregoing results that the present inventioncan be effective also when the surface layer is a layer containing O(oxygen).

                  TABLE 48    ______________________________________    Conditions for Surface Layer Formation    Surface layer    ______________________________________    SiH.sub.4            50 SCCM    NO                   900 SCCM    Power                100 W    Internal pressure    0.4 Torr    Layer thickness      0.1 μm    ______________________________________

EXPERIMENTAL EXAMPLE 29

A lower blocking layer and a photoconductive layer were formed in thesame manner as in Experimental Example 20. Thereafter, a surface layerwas formed under conditions as shown in Table 49. In this surface layerformation, the deposited films constituting the surface layer wereformed in a layer thickness of 1,000 Å for each time. The deposited filmthus formed was subjected to fluorine treatment under conditions asshown in Table 44 to carry out etching in a depth of 500 Å.Subsequently, the operation to form another deposited film in athickness of 1,000 Å and to again make the fluorine treatment underconditions as shown in Table 44 to carry out etching in a depth of 500Å, was repeated. This film formation and etching for the surface layerwere repeated plural times so as to provide a layer thickness of 3,000 Åin total to form a surface layer containing fluorine atoms.

The contact angle of the surface of the light-receiving member thusformed was measured. As a result, it showed a contact angle of 100degrees or greater, having achieved a high water repellency.

This light-receiving member was running tested in the same manner as inExperimental Example 1 to find that it similarly had superiorperformances.

It has been found from the foregoing results that the present inventioncan be effective also when the light-receiving member has a layerconfiguration where a-BN (amorphous boron nitride) is used in thesurface layer.

                  TABLE 49    ______________________________________    Conditions for Surface Layer Formation    Surface layer    ______________________________________    B.sub.2 H.sub.6      300 SCCM    N.sub.2              600 SCCM    Power                100 W    Internal pressure    0.4 Torr    Layer thickness      0.1 μm    ______________________________________

Effect of the invention:

As having been described above in detail, in the present invention thesurface layer of the light-receiving member is formed by repeatingplural times film formation and etching using a fluorine type gas.Hence, fluorine atoms are effectively incorporated into the surfacelayer. When this is used in electrophotographic apparatus, it ispossible to well prevent the corona discharge products from adheringeven if the steps of charging, exposure, development, transfer,separation and cleaning are repeated. Also, the hardness required as asurface protective layer is by no means damaged, and hence the surfacelayer can maintain the water repellency even if the outermost surface ofthe light-receiving member has abraded as a result of long-termrepetition of scrape cleaning by means of a blade, and can besubstantially free from the changes in moisture adsorption that arecaused by differences in environment. Thus, it has become possible toprevent smeared images and faint images from occurring even if noheating means for the light-receiving member is provided. Moreover, thelight-receiving member can have a superior cleaning performance, and canmaintain the cleaning performance even when the copying process isrepeated many times. Thus, it has become possible to prevent unevenimage density due to the wire contamination of the corona assembly,caused by the scatter of toner. In addition, since the heating of thelight-receiving member is unnecessary, the types of usable toners can begreatly broadened.

Needless to say, the present invention allows appropriate modificationand combination within the range of the gist of the invention, and is byno means limited to the embodiments described above.

What is claimed is:
 1. A process for producing a light-receiving memberwhich comprises the steps of:(a) forming an outer layer on the surfaceof a light-receiving layer, said light-receiving layer supported by asubstrate, said outer layer comprising a non-single-crystalline materialcontaining silicon atoms and at least one kind of carbon atoms, oxygenatoms or nitrogen atoms; (b) etching the surface of the outer layer soas to remove a portion of the outer layer; (c) forming a second outerlayer of a non-single crystalline material containing silicon atoms andat least one kind of carbon atoms, oxygen atoms or nitrogen atoms on thesurface of the remaining outer layer after the step (b) is conducted;and (d) etching the surface of the second outer layer formed in the step(c), to form a surface layer on the light-receiving layer.
 2. Theprocess for producing a light-receiving member according to claim 1,wherein the etching is carried out by using a gas comprising fluorine.3. The process for producing a light-receiving member according to claim2, wherein the gas comprising fluorine contains at least one of CF₄,CHF₃, C₂ F₆ or ClF₃.
 4. The process for producing a light-receivingmember according to claim 1, wherein the surface layer is formed byutilizing a frequency of 50 MHz to 450 MHz.
 5. The process for producinga light-receiving member according to claim 1, wherein the surface layerfurther contains hydrogen atoms.
 6. The process for producing alight-receiving member according to claim 1, wherein thickness of theouter layer etched in the step (b) or (d) is at least 20 Å.
 7. Theprocess for producing a light-receiving member according to claim 1,wherein thickness of the outer layer etched in the step (b) or (d) is atleast 50 Å.
 8. The process for producing a light-receiving memberaccording to claim 1, wherein thickness of the outer layer formed in thestep (a) or (c) 30 Å to 2,500 Å.
 9. The process for producing alight-receiving member according to claim 1, wherein thickness of theouter layer formed in the step (a) or (c) is 60 Å to 1,000 Å.
 10. Theprocess for producing a light-receiving member according to claim 1,wherein thickness of the surface layer to be formed is 10 Å to 2,000 Å.11. The process for producing a light-receiving member according toclaim 1, wherein thickness of the surface layer to be formed is 40 Å to1,000 Å.
 12. The process for producing a light-receiving memberaccording to claim 1, wherein the formation of the outer layer in thesteps (a) and (c) and the etching of the outer layer in the steps (b)and (d) result in formation of a surface layer region containing bondedfluorine atoms in the surface layer.
 13. The process for producing alight-receiving member according to claim 12, wherein the region has athickness of from 1 Å to 500 Å.
 14. The process for producing alight-receiving member according to claim 1, wherein the light-receivinglayer is photoconductive.
 15. The process for producing alight-receiving member according to claim 1, wherein the light-receivinglayer comprises a photoconductive layer.
 16. The process for producing alight-receiving member according to claim 15, wherein thephotoconductive layer is a single layer.
 17. The process for producing alight-receiving member according to claim 15, wherein thephotoconductive layer is functionally separated into a charge generatinglayer and a charge transporting layer.
 18. The process for producing alight-receiving member according to claim 1, wherein a charge injectionblocking layer is interposed between the substrate and thelight-receiving layer.
 19. The process for producing a light-receivingmember according to claim 1, wherein the light-receiving layer comprisesa matrix of a non-single-crystalline material comprising silicon atoms.20. The process for producing a light-receiving member according toclaim 1, wherein the outer layer of the non-single-crystalline materialformed in the step (a) or (c) comprises an amorphous material.
 21. Theprocess for producing a light-receiving member according to claim 1,wherein the etching in the step (b) or (d) is carried out by utilizing afrequency of 50 MHz to 450 MHz.
 22. The process for producing alight-receiving member according to claim 1, wherein the formation ofthe outer layer in the step (a) or (c) and the etching in the step (b)or (d) are carried out by utilizing a frequency of 50 MHz to 450 MHz.23. The process for producing a light-receiving member according toclaim 1, wherein the light-receiving layer is formed by utilizing afrequency of 1 MHz to 450 MHz.
 24. The process for producing alight-receiving member according to claim 1, wherein the content of theat least one kind of carbon atoms, oxygen atoms or nitrogen atoms in thesurface layer increases toward the exposed surface.
 25. The process forproducing a light-receiving member according to claim 1, wherein afterstep (d) is conducted, the steps (b), (c) and (d) are repeated to etchthe surface layer, to form an additional outer layer and to etch thesurface of the additional outer layer to form a second surface layer.26. The process for producing a light-receiving member according toclaim 1, wherein the surface layer further contains hydrogen atoms. 27.A process for producing a light-receiving member which comprises thesteps of:(a) forming an outer layer on the surface of a light-receivinglayer, said light-receiving layer supported by a substrate, said outerlayer comprising a non-single-crystalline material comprising carbonatoms; (b) etching the surface of the outer layer so as to remove aportion of the outer layer; (c) forming a second outer layer of anon-single-crystalline material containing carbon atoms on the surfaceof the remaining outer surface after the step (b) is conducted; and (d)etching the surface of the second outer layer formed in the step (c), toform a surface layer on the light-receiving layer.
 28. The process forproducing a light-receiving member according to claim 27, wherein thelight-receiving layer comprises a matrix of a non-single-crystallinematerial comprising silicon atoms.
 29. The process for producing alight-receiving member according to claim 27, wherein the thickness ofthe outer layer etched in the step (b) or (d) is at least 20 Å.
 30. Theprocess for producing a light-receiving member according to claim 27,wherein the thickness of the outer layer etched in the step (b) or (d)is at least 50 Å.
 31. The process for producing a light-receiving memberaccording to claim 27, wherein the thickness of the outer layer formedin the step (a) or (c) is 30 Å to 2,500 Å.
 32. The process for producinga light-receiving member according to claim 27, wherein the thickness ofthe outer layer formed in the step (a) or (c) is 60 Å to 1,000 Å. 33.The process for producing a light-receiving member according to claim27, wherein the thickness of the surface layer to be formed is 10 Å to2,000 Å.
 34. The process for producing a light-receiving memberaccording to claim 27, wherein the thickness of the surface layer to beformed is 40 Å to 1,000 Å.
 35. The process for producing alight-receiving member according to claim 27, wherein the formation ofthe outer layer in the steps (a) and (c) and the etching of the outerlayer in the steps (b) and (d) result in formation of a surface layerregion containing bonded fluorine atoms in the surface layer.
 36. Theprocess for producing a light-receiving member according to claim 35,wherein the region has a thickness of from 1 Å to 500 Å.
 37. The processfor producing a light-receiving member according to claim 27, whereinthe light-receiving layer is photoconductive.
 38. The process forproducing a light-receiving member according to claim 27, wherein thelight-receiving layer comprises a photoconductive layer.
 39. The processfor producing a light-receiving member according to claim 38, whereinthe photoconductive layer is a single layer.
 40. The process forproducing a light-receiving member according to claim 38, wherein thephotoconductive layer is functionally separated into a charge generatinglayer and a charge transporting layer.
 41. The process for producing alight-receiving member according to claim 38, wherein thephotoconductive layer comprises a charge transport layer and a chargegeneration layer.
 42. The process for producing a light-receiving memberaccording to claim 27, wherein a charge injection blocking layer isinterposed between the substrate and the light-receiving layer.
 43. Theprocess for producing a light-receiving member according to claim 27,wherein the outer layer of the non-single-crystalline material formed inthe step (a) or (c) comprises an amorphous material.
 44. The process forproducing a light-receiving member according to claim 27, wherein thesurface layer is formed by utilizing a frequency of 50 MHz to 450 MHz.45. The process for producing a light-receiving member according toclaim 27, wherein the etching in the step (b) or (d) is carried out byutilizing a frequency of 50 MHz to 450 MHz.
 46. The process forproducing a light-receiving member according to claim 27, wherein theformation of the outer layer in the step (a) or (c) and the etching inthe step (b) or (d) are carried out by utilizing a frequency of 50 MHzto 450 MHz.
 47. The process for producing a light-receiving memberaccording to claim 27, wherein the light-receiving layer is formed byutilizing a frequency of 1 MHz to 450 MHz.
 48. The process for producinga light-receiving member according to claim 27, wherein after step (d)is conducted the steps (b), (c) and (d) are repeated to etch the surfacelayer, to form an additional outer layer and to etch the surface of theadditional outer layer to form a second surface layer.
 49. The processfor producing a light-receiving member according to claim 27, whereinthe layer formed in the step (a) further contains silicon atoms.
 50. Theprocess for producing a light-receiving member according to claim 27,wherein the etching steps (b) and (d) are carried out by using a gascontaining fluorine.
 51. The process for producing a light-receivingmember according to claim 50, wherein the gas containing fluorineincludes at least one of CF₄, CHF₃, C₂ F₆ or ClF₃.
 52. A process forproducing a light-receiving member comprising the steps of:(a) etching alight-receiving layer on a substrate to remove a portion of thelight-receiving layer; (b) forming on the surface of the light-receivinglayer an outer layer, said outer layer comprising (i) a non-singlecrystalline material containing silicon atoms and at lease one kind ofcarbon atoms, oxygen atoms or nitrogen atoms or (ii) anon-single-crystalline material containing carbon atoms; and (c) etchingthe surface of the outer layer so as to remove a portion of the outerlayer to form a surface layer.
 53. The process for producing alight-receiving member according to claim 52, wherein the etching iscarried out by using a gas comprising fluorine.
 54. The process forproducing a light-receiving member according to claim 52, wherein afterstep (c) is conducted, conducting at least once the steps of etching thesurface layer to remove a portion thereof; forming a second outer layerhaving the substituents of the outer layer of step (b) and etching thesurface of the second outer layer to form a second surface layer.
 55. Aprocess for producing a light-receiving member which comprises the stepsof:(a) forming an outer layer on the surface of a light-receiving layer,said light-receiving layer supported by a substrate, said outer layercomprising a non-single-crystalline material containing boron atoms andnitrogen atoms; (b) etching the surface of the outer layer so as toremove a portion of the outer layer; (c) forming a second outer layer ofa non-single-crystalline material containing boron atoms and nitrogenatoms on the surface of the remaining outer surface after the step (b)is conducted; and (d) etching the surface of the second outer layerformed in the step (c), to form a surface layer on the light-receivinglayer.
 56. The process for producing a light-receiving member accordingto claim 55, wherein the etching steps (b) and (d) are carried out byusing a gas containing fluorine.
 57. The process for producing alight-receiving member according to claim 56, wherein the gas containingfluorine includes at least one of CF₄, CHF₃, C₂ F₆ and ClF₃.
 58. Theprocess for producing a light-receiving member according to claim 55,wherein the thickness of the outer layer etched in the step (b) or (d)is at least 20 Å.